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Publisher: John Wiley and Sons   (Total: 1589 journals)

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Showing 1 - 200 of 1589 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 65, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 48, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 53, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 168, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 6, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 37, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 7, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 5)
Addiction     Hybrid Journal   (Followers: 36, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 14, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 26, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 51, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 14, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 295, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 7, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 21)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 13)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 11)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 16, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 11, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 3, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 16, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 32, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 33, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 51, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 152, SJR: 0.951, h-index: 61)
American Business Law J.     Hybrid Journal   (Followers: 24, SJR: 0.205, h-index: 17)
American Ethnologist     Hybrid Journal   (Followers: 93, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 29, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 35, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 13, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 16, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 4, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 6, SJR: 2.315, h-index: 79)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 37, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 290, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 16, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 18, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 138, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 9, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 20)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 179)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 229, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 41, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 7, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 48, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 1, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 8, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 13)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 25, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 17, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 15)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 91, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 50, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 8, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 70, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 209, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 50, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 14, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 32, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 36, SJR: 1.047, h-index: 57)
Arabian Archaeology and Epigraphy     Hybrid Journal   (Followers: 11, SJR: 0.453, h-index: 11)
Archaeological Prospection     Hybrid Journal   (Followers: 12, SJR: 0.922, h-index: 21)
Archaeology in Oceania     Hybrid Journal   (Followers: 13, SJR: 0.745, h-index: 18)
Archaeometry     Hybrid Journal   (Followers: 29, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 15, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 26, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 3, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 5)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 13, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 274, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 54, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 27, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 15)
Asia & the Pacific Policy Studies     Open Access   (Followers: 16)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 326, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (Followers: 1, SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 8, SJR: 0.345, h-index: 20)
Asia-pacific J. of Clinical Oncology     Hybrid Journal   (Followers: 6, SJR: 0.554, h-index: 14)
Asia-Pacific J. of Financial Studies     Hybrid Journal   (SJR: 0.241, h-index: 7)
Asia-Pacific Psychiatry     Hybrid Journal   (Followers: 4, SJR: 0.377, h-index: 7)
Asian Economic J.     Hybrid Journal   (Followers: 8, SJR: 0.234, h-index: 21)
Asian Economic Policy Review     Hybrid Journal   (Followers: 4, SJR: 0.196, h-index: 12)
Asian J. of Control     Hybrid Journal   (SJR: 0.862, h-index: 34)
Asian J. of Endoscopic Surgery     Hybrid Journal   (Followers: 1, SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 6, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 12, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 3, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 15, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 9, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 6, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 14, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 3, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 47, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 6, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 6, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 31, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 15, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 18, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 419, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 5, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 72, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 23, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 36, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 11, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 5, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 24, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 16, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 5, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 41, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 37, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 44, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 152, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 14, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 20, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 38, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 7, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)
BJOG : An Intl. J. of Obstetrics and Gynaecology     Partially Free   (Followers: 247, SJR: 2.083, h-index: 125)

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Journal Cover Advances in Polymer Technology
  [SJR: 0.344]   [H-I: 31]   [13 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0730-6679 - ISSN (Online) 1098-2329
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Solid-state foaming of epoxy resin under hypergravity and simulated
           microgravity
    • Authors: Fabrizio Quadrini; Giovanni Matteo Tedde, Loredana Santo, Jack J.W.A. Loon
      Abstract: Solid-state foaming of epoxy resins has been performed under simulated microgravity by the random positioning machine (RPM) and under hypergravity by the large diameter centrifuge (LDC). More than 50 tests have been performed in static and dynamic conditions in different experimental configurations. Longitudinal, radial, and volumetric foaming ratios have been extracted from foaming tests, and correlated with the applied gravity conditions. Results show that the gravity vector has two opposite effects; the first on the flow front movement and the second on the contact between the sample and the oven. The second effect seems to be stronger, and the important role of heat transfer is confirmed. Nevertheless, effects related to apply centrifugal forces have been found and discussed, above all in the case of LDC tests.
      PubDate: 2018-01-17T01:46:33.105066-05:
      DOI: 10.1002/adv.21937
       
  • Effects of monomer length on α-olefins polymerization using a
           conventional Ziegler–Natta catalyst
    • Authors: Sedigheh Shirbakht; Seyed Amin Mirmohammadi, Khadijeh Didehban, Samaheh Sadjadi, Naeimeh Bahri-Laleh
      Abstract: α-Olefin monomers with different lengths from C4 to C10 were polymerized via a conventional Ziegler–Natta catalyst. It was found that activity of the catalyst decreases with increase in the monomer length as well as introduction of external donor. GPC results exhibited a steady decrease in molecular weight from poly1-butene to poly1-decene; however, PDI did not show a clear trend. Based on differential scanning calorimetry and X-ray diffraction analyses, poly1-butene and poly1-decene represented crystalline structure with one and two melting points, respectively, while poly1-hexene and poly1-octene showed amorphous nature. The content of isotactic pentads increased from poly1-butene to poly1-octene, with maximum value of mmmm = 76%, but decreased again in poly1-decene. Calculated ΔEre-si values showed a peak by increasing monomer length which was in line with the experimental results for isotactic content.
      PubDate: 2018-01-15T02:40:37.551321-05:
      DOI: 10.1002/adv.21934
       
  • Graphene oxide, an effective nanoadditive for a development of hollow
           fiber nanocomposite membrane with antifouling properties
    • Authors: Javed Alam; Arun Kumar Shukla, Mansour Alhoshan, Lawrence Arockiasamy Dass, Muthu Ramamoorthy Muthumareeswaran, Aslam Khan, Fekri Abdulraqeb Ahmed Ali
      Abstract: A series of hollow fiber (HF) membranes made from nanocomposites of polyethersulfone (PES) and graphene oxide (GO) at GO concentrations of 0.2%, 0.5%, and 1.0% were prepared by the dry–wet spinning process. The structure and the properties of as-prepared HF membranes were characterized by scanning electron microscopy (SEM); atomic force microscopy (AFM); measurements of contact angle, zeta potential, molecular weight cut-off (MWCO), and porosity; thermogravimetric analysis (TGA); and tensile testing. Long-term filtration tests were performed with the proteins bovine serum albumin (BSA), pepsin, trypsin, and lysozyme, which are common model organic foulants used in membrane fouling studies. The results showed that HF membrane made from PES/GO nanocomposite dope had a water permeability of 30 ± 1.5 Lm−2 hr−1 bar−1, which is an increase of approximately 36% compared to that of a PES HF membrane. Among the membranes containing GO, the membrane with a 0.5 wt% GO loading exhibited the best antifouling performance, that is, this membrane recovered more than approximately 96% of its initial pure water flux, demonstrating a high resistance to the irreversible fouling. In addition, the same membrane showed an improvement in MWCO, an approximately 15% increase in porosity, along with optimum mechanical and thermal properties.
      PubDate: 2018-01-15T02:36:29.564696-05:
      DOI: 10.1002/adv.21935
       
  • Sorption behavior of methylene blue and rhodamine B mixed dyes onto
           chitosan graft poly (acrylic acid-co-2-acrylamide-2-methyl propane
           sulfonic acid) hydrogel
    • Authors: Yaoji Tang; Tengteng He, Yangwenyi Liu, Bin Zhou, Rui Yang, Linhui Zhu
      Abstract: Chitosan graft poly(acrylic acid-co-2-acrylamide-2-methyl propane sulfonic acid) (CTS-g-P(AA-co-AMPS)) hydrogel is prepared and used to remove methylene blue (MB) and rhodamine B (RB) mixed dyes from aqueous solutions. The effect of adsorption conditions, including the initial concentrations of dye solutions, contact time, initial pH values, ionic strength, and the adsorbent dosage, on the adsorption capacities is investigated. The maximal adsorption capacity for MB and RB is 936.0 and 556.9 mg/g, respectively. The adsorption isotherms of the mixed dyes are discussed using the extended Langmuir (EL) and the extended Freundlich (EF) isotherm equations. It indicates that the adsorption of both dyes is in good agreement with the extended Freundlich isotherm. Meanwhile, the adsorption processes of both dyes are spontaneous. Adsorption kinetics is in accordance with the pseudo-second-order kinetic equation. It is concluded that the available adsorption sites are shared by both kinds of the dye molecules. The difference of the maximal adsorption capacities of the two dyes is due to their different affinity to the adsorbent.
      PubDate: 2018-01-02T00:46:27.501458-05:
      DOI: 10.1002/adv.21932
       
  • Prediction of part geometry-dependent weld line strength in unreinforced
           polycarbonate
    • Authors: Christian Hopmann; Jakob Onken
      Abstract: To predict the mechanical properties of weld lines in injection-molded unreinforced amorphous plastics parts, an integrative calculation chain has been developed. Weld lines created by different flow obstacle geometries were characterized through mechanical testing. A strong dependence of the weld line strength on the geometry of the flow obstacle and the distance to the flow obstacle, which causes the weld line, was observed. Further, a dependence of the weld line strength on the loading direction was noted. These results were used to establish a simulation routine which is based on a physical description of molecular interdiffusion and uses the melt confluence angles in the weld line to determine weld line annealing behind flow obstacles. The calculated breaking stress of weld lines in polycarbonate using the model deviates on average 14% from the fracture stress that was determined experimentally.
      PubDate: 2018-01-02T00:46:20.234214-05:
      DOI: 10.1002/adv.21933
       
  • Synthesis of polycarboxylate superplasticizers using an acrylic acid-rich
           wastewater from acrolein production
    • Authors: Jikai Pei; Ziwei Wang, Jianguo Ren, Diansheng Liu
      Abstract: In this paper, an acrylic acid-rich wastewater from the production of propylene to acrolein was used to synthesize the polycarboxylate superplasticizers. First, the acrylic acid-rich wastewater was oxidized. Then, two kinds of unsaturated polyether macromonomers {methallyl polyethylene glycol (HPEG) and isoprenol polyethylene glycol (IPEG)} and the oxidized wastewater were copolymerized with it, respectively, by free radical polymerization in aqueous solution. The monomer conversion, molecular weight, molecular weight distribution of the copolymers of gel permeation chromatography (GPC) were characterized. The performance of the two copolymers was characterized by measuring paste flow, adsorption using GPC method, and the applied behavior of premixed concrete. The results showed that the synthesized copolymers could meet the requirement of application in contrast to the commodity product.
      PubDate: 2017-12-28T04:35:40.647558-05:
      DOI: 10.1002/adv.21931
       
  • Effects of composition and temperature of initial mixture on the formation
           and properties of polyurethane foam
    • Authors: İ. Bedii Özdemir; Fırat Akar
      Abstract: The purpose of the study is to optimize the initial conditions of the molding process of a multicomponent mixture into a refrigerator cabinet. Polyurethane foaming has been studied with different starting compositions and temperatures of the initial mixture. The kinetic mechanism has involved four reactions and species species. Using a standard recipe, the chemical kinetics and the numerical implementation have been first validated against the experimental values of the filling time and the density of the final foam. Thereafter, 11,763 different initial conditions are calculated. The results put in evidence that the filling time can be reduced without any significant change in the precursors of the rigidity of the foam. The final temperature of the foam has always remained lower than the limiting temperature so that thermal material deformations in the walls of the cabinet can be avoided. Increasing the physical blowing agent mass fraction beyond the standard recipe does not appear to be a useful option.
      PubDate: 2017-12-28T04:31:08.37073-05:0
      DOI: 10.1002/adv.21927
       
  • Thermal, mechanical properties and morphology of epoxy resins modified
           with light pyrolysis natural rubber
    • Authors: Xinyu Zhao; Shifeng Wang
      Abstract: Instead of using traditional functional liquid rubbers in toughening epoxy, light pyrolysis natural rubber (LPNR) obtained from scrap rubber was introduced to improve the toughness of cured epoxy resins. Epoxy blends were prepared by physically mixing the epoxy resins with various concentrations of LPNR. The structure, thermal, mechanical properties and morphology of the epoxy blends were investigated by Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, impact behavior, and scanning electron microscopy. It was found that the inclusion of 5 phr LPNR reached the maximum value in impact strength of the modified epoxies and the presence of LPNR enables the epoxy resins to fracture in a pattern more akin to ductile materials than in case of the neat epoxy which shows features of brittle rupture. The agglomeration of rubber particles decreased the toughness of epoxy resins modified with more LPNR. Meanwhile, the nearly unchanged glass transition temperature of LPNR epoxy samples illustrated weak interfacial adhesion existed between the rubber phase and epoxy matrix due to low compatibility and feeble combination between them. The thermal stability of modified epoxy resins went down because of the existence of LPNR domains inside the matrix. Overall, the LPNR should be further investigated to improve its compatibility and reinforce its combination with the epoxy resins to become a particularly efficient toughening agent because of its cheaper resource and contribution to environmental protection.
      PubDate: 2017-12-25T22:15:39.905834-05:
      DOI: 10.1002/adv.21929
       
  • Polylactic acid–agave fiber biocomposites produced by rotational
           molding: A comparative study with compression molding
    • Authors: Erick Omar Cisneros-López; Aida Alejandra Pérez-Fonseca, Yolanda González-García, Daniel Edén Ramírez-Arreola, Rubén González-Núñez, Denis Rodrigue, Jorge Ramón Robledo-Ortíz
      Abstract: In this work, the possibility to produce polylactic acid (PLA) and agave fiber biocomposites by dry-blending and rotational molding was studied. The samples were also produced by compression molding to compare the effect of processing conditions on the biocomposites properties. In particular, the effect of fiber content (0–40 wt.%) on morphology, density, porosity, thermal (DSC) and mechanical properties (tension, flexion, impact and hardness) was studied. Also, a complete analysis of the internal air temperature profiles was performed to determine the thermal behavior of PLA during the rotational molding cycle. The results showed that rotomolded biocomposites were successfully produced but had higher porosity than compression molded ones due to the absence of pressure while forming. This led to different level of mechanical properties reduction as fiber content increases. Nevertheless, for compression-molded biocomposites, crystallinity (30% at 30 wt.%), tensile modulus (14% at 30 wt.%) and impact strength (71% at 40 wt.%) improvements were obtained compared to neat PLA.
      PubDate: 2017-12-25T22:12:06.04709-05:0
      DOI: 10.1002/adv.21928
       
  • Preparation of hierarchical carbon nanotube–carbon fiber composites with
           coordination enhancement
    • Authors: Han Xue; Nuona A, Yinghong Xiao, Jianfei Che
      Abstract: Single-walled carbon nanotubes–carbon fiber (SWNTs@CF) hierarchical fibers were prepared by electrophoretic deposition. To improve the interfacial strength between SWNTs and CF, a hexahapto-metal complex, Cr(CO)6, was added to the electrophoretic system to prepare hierarchical fibers (SWNTs-Cr(CO)6@CF). Results revealed that SWNTs covered CF surface entirely and formed a hierarchical structure. The morphology could be tailored from scattered nanotubes over forest to network by varying the deposition voltage. The hierarchical fibers were highly compatible with epoxy matrix, which could significantly increase the interfacial adhesion through interlocking epoxy matrix. Tensile properties were studied to investigate the effect of interfacial adhesion on mechanical properties of the reinforced composites. The polymeric composite, reinforced by SWNTs-Cr(CO)6@CF, exhibited a remarkably high tensile strength of 519 MPa with the content ratio of 1.5:1 (Cr(CO)6:SWNTs). The improvement was up to 193% compared to the desized CF composite and 19% compared to SWNTs@CF composite. Additionally, thermogravimetric analyses demonstrated that the SWNTs-Cr(CO)6@CF composite exhibited superior heat stability.
      PubDate: 2017-12-25T20:30:46.026671-05:
      DOI: 10.1002/adv.21930
       
  • Mechanical, thermal, and water absorption properties of wheat
           straw/bagasse-reinforced epoxy blended composites
    • Authors: Varun Mittal; Shishir Sinha
      Abstract: This study is to investigate the mechanical, thermal, and water absorption properties of wheat straw and bagasse fiber-reinforced epoxy blended composites. To enhance these properties, wheat straw fiber was blended with bagasse fiber. The wheat straw and bagasse fibers were prepared with various weight ratios (80/20, 60/40, 40/60, and 20/80) and then incorporated into the epoxy matrix by molding technique to form composites. The mechanical, thermal, and water absorption characteristics were examined using blended composite samples. In this research, it has been observed that increases in the bagasse fiber content in wheat straw/epoxy composites result in superior the mechanical, thermal, and decreasing the moisture absorption property. A scanning electron microscope was used to observe the fracture surface of the samples.
      PubDate: 2017-12-20T02:17:23.468896-05:
      DOI: 10.1002/adv.21924
       
  • Improved interfacial properties of carbon fiber composites by building
           stress transition layer with carbon nanotubes
    • Authors: Wenqing Zhang; Qing Yang, Xi Deng, Gang Bai, Wei Xiao, Gang Sui, Xiaoping Yang
      Abstract: For the purpose of improvement in interfacial property of carbon fiber composites through a facile process, the carboxyl-functionalized multiwalled carbon nanotubes (MWCNTs-COOH) were incorporated into the surface of JH-T800 carbon fiber using sizing and deposition technology. The surface morphology of MWCNTs-COOH-modified carbon fibers and fracture surfaces of unidirectional carbon fiber composites were observed via scanning electron microscopy and atomic force microscopy. According to the results of composites fragmentation test, the adoption of MWCNTs-COOH-modified carbon fibers resulted in the improved carbon fiber/epoxy matrix interfacial bonding and interlaminer property by 32.1% and 31.9%, respectively. Through the combination of the above two kinds of pretreating process of carbon fibers, a stress transition layer with the gradient distribution of MWCNTs was built between carbon fiber and resin matrix, which was favorable for releasing stress concentration and hindering the propagation of crack, resulting in a higher reinforcing efficiency for the existing carbon fiber composites.
      PubDate: 2017-12-18T04:22:33.289738-05:
      DOI: 10.1002/adv.21926
       
  • Numerical study of mixing dynamics inside the novel elements of a
           corotating nontwin screw extruder
    • Authors: Baiping Xu; Yao Liu, Liang He, Jinwei Chen, Lih-Sheng Turng
      Abstract: A novel, self-cleaning, corotating nontwin screw configuration is proposed, and its geometry is briefly introduced in this study. In this new configuration, one single-tip screw element intermeshes with another two-tip screw element at a speed ratio of 2. A numerical simulation of the three-dimensional flow field in this new kind of conveying system, as well as in the conventional twin screw configuration, was carried out using the finite element method (FEM) and the mesh superposition technique (MST) provided by the commercial CFD code POLYFLOW. The purely viscous fluid is assumed to obey the Bird–Carreau constitutive model. Based on the predicted flow field in the domain FEM mesh, post-treatment codes have been developed to predict the mixing details where standard fourth-order Runge–Kutta schemes were used. Flow patterns and mixing dynamics were presented in terms of the mixing evolution of the particle group released from different initial positions and the variation of the variance index, mixing index, strain tensor magnitude, and their time histories. Trajectories of the particle groups were captured successfully, and an obvious difference with regard to flow pattern and mixing was found for different types of screw geometries. The numerical results showed that mixing was highly dependent on the initial position of the particles and that the nontwin screw configuration had better distributive and dispersive mixing abilities than the conventional twin screw configuration.
      PubDate: 2017-12-13T03:39:41.391185-05:
      DOI: 10.1002/adv.21923
       
  • Softening dynamics of polymer blends and composites investigated by
           differentia spectra of dynamic mechanical analysis
    • Authors: Rui Zhang; Xianru He, Alisson M. Rodrigues, Qipeng Guo
      Abstract: The confinement effect on molecular motions has been widely observed in polymeric blends and composites. For polymers that have softening dynamics in glass–rubber transition region, the confinement effect can influence the molecular motions to different degrees. In this work, the differentia spectra of dynamic mechanical analysis were applied to analyze the confinement effect in butyl rubber (IIR)/ethylene-vinyl acetate copolymer (EVA) blends, IIR/high-density polyethylene (HDPE) blends, chlorobutyl rubber (CIIR)/polystyrene (PS) blends, IIR/silica composites, and CIIR/organophilic montmorillonite (OMMT) composites. In the differentia spectra, the confinement effect from additional components on local segment motions (LSM), sub-Rouse modes, and Rouse modes was investigated, indicating that the effect on sub-Rouse modes is smaller than that on Rouse modes but larger than that on LSM. Moreover, the coupling effects slightly change with introduction of the secondary components, which enables us to assume that the confinement effect has a linear relationship with the content of secondary components. Finally, it has been found that the decrease in tan δ exhibited a linear relationship with the content of secondary components.
      PubDate: 2017-12-11T23:31:56.097783-05:
      DOI: 10.1002/adv.21925
       
  • Fabrication of self-reinforced polyester composites and their mechanical
           and flame retardant properties
    • Authors: Zhang Wei; Nabeel Ahmed Syed, Latif Muhammad, Song Jung-IL
      Abstract: Self-reinforced polyester composites (SRPCs) with light weight, high mechanical properties, good interfacial bonding, and easy to recycle at the end after use have been developed to replace traditional synthetic fiber-reinforced plastics. This study is on fabrication of SRPCs is performed using polyethylene terephthalate (PET) as matrix and polybutylene terephthalate (PBT) as reinforcement material through compression molding via film stacking method. The compression molding parameters such as temperature, pressure, and dwell time were optimized by Taguchi method, and these values are 225°C, 8 MPa, 5 min for tensile strength, 225°C, 5 MPa, 15 min for flexural, and 215°C, 3 MPa, 5 min for impact test. Flame retardancy in SRPCs has also been introduced as a new idea to minimize the flammability nature and is helpful in engineering applications. Flame retardants (FRs) such as ammonium polyphosphate (APP), zinc borate (Zb), and magnesium hydroxide (Mg(OH)2) were used. The flame retardancy mechanism of optimized SRPCs works effectively which was evident by horizontal burning and LOI test. Thermogravimetric analysis (TGA) was also studied to confirm the thermal properties of the composites. Mechanical properties were reasonably affected by the FRs as confirmed by field emission scanning electron microscope (FESEM).
      PubDate: 2017-12-11T23:27:32.265632-05:
      DOI: 10.1002/adv.21918
       
  • Enhanced thermal stability and flame resistance of polyurethane-imide
           foams by adding silicon carbide
    • Authors: Huafeng Tian; Yuanyuan Yao, Songbai Ma, Jiali Wu, Aimin Xiang
      Abstract: Polyurethane-imide (PUI) foams containing both polyimide and polyurethane segments combined the advantage of fine mechanical properties as well as high thermal stability of the two polymers. To further improve the thermal stability and flame resistance of PUI foams, a series of PUI composite foams with different content of SiC (silicon carbide) as fillers were prepared. The cell structure, mechanical properties, flame resistance, and thermal properties of resulting PUI/SiC composite foams were characterized in detail. The experimental results showed that the cell size distribution became uneven, the apparent density was increased, and the compressive strength decreased with the increase in silicon carbide content. Meanwhile, the limiting oxygen index (LOI) showed an increase from 24.7% to 28.1% with increasing of SiC content from 0% to 9.6%. The thermogravimetric analysis showed that the addition of SiC could significantly enhance the thermal stability and flame retardancy of PUI foams.
      PubDate: 2017-12-11T23:26:49.66181-05:0
      DOI: 10.1002/adv.21922
       
  • A novel process for processing aqueous insoluble
           3,4-propylenedioxythiophene
    • Authors: Bikash Kumar Sikder
      Abstract: The present article discusses the development of aqueous dispersions of 3,4-propylenedioxythiophene (ProDOT) with polystyrene sulfonate (PSS) for the first time in literature. Unlike 3,4-ethylenedioxythiophene (EDOT), ProDOT is solid and insoluble in water, and hence requires specific reaction condition such as acidic media and sonication to polymerize through emulsion polymerization technique to form PProDOT:PSS complex. PProDOT:PSS aqueous dispersion was characterized and studied using UV-vis spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscope. Particle size distribution, stability, and ion content of the dispersion were determined using dynamic light scattering, zeta potential, and inductive coupled plasma-atomic emission spectrometry studies, respectively. Effect of organic solvents such as ethylene glycol, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), and sorbitol on the conductivity and morphology of PProDOT:PSS films was investigated.
      PubDate: 2017-12-08T02:13:02.723947-05:
      DOI: 10.1002/adv.21915
       
  • Characterization and mechanical properties of cellulose acetate/carbon
           nanotube composite nanofibers
    • Authors: Ahmed Salama; Alaa Mohamed, Nada M. Aboamera, Tarek Osman, Aly Khattab
      Abstract: Cellulose acetate/carbon nanotube composite nanofibers were prepared using electrospinning technique. The morphology, crystalline, and mechanical properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and tensile test. The result indicated that the CA with 0.5 wt% CNT shows better mechanical properties among the other sample which contains lower or higher percent of CNT. In addition, the diameter of the average fibers was 415 ± 45 nm and shows good dispersions of CNT into the nanofibers. Moreover, tensile strength and Young's modulus were enhanced with an average of 67% and 78%, respectively.
      PubDate: 2017-12-08T02:08:37.667844-05:
      DOI: 10.1002/adv.21919
       
  • Experimental study and evaluation of mixing mechanism and performance in
           triple-screw extruder
    • Authors: Kunxiao Yang; Chunling Xin, Dongquan Yu, Baorui Yan, Yadong He
      Abstract: The mixing capacity of triangle-arrayed triple-screw extruder (TTSE) was evaluated through the extrusion of polypropylene/ethylene–propylene–diene monomer (PP/EPDM) at varying screw speeds. The micromorphology, mean residence time, melt flow rate (MFR), and mechanical properties of blends were measured for evaluation. Moreover, same experiments were applied on a twin-screw extruder (TSE) for comparison. TTSE shows better mixing performance than TSE in comparison with micromorphology and mean residence time. But the high shear effect and temperature rising in TTSE promote the degradation of PP in blends which make the samples to have worse mechanical properties and higher MFR than those of TSE.
      PubDate: 2017-12-01T04:36:13.798296-05:
      DOI: 10.1002/adv.21920
       
  • Influence of bleaching treatment by hydrogen peroxide on chitosan/durian
           husk cellulose biocomposite films
    • Authors: Jason Yit Meng Wong; Ming Yeng Chan
      Abstract: This study covered the preparation and characterization of durian husk cellulose (DHC)-filled chitosan (CS) biocomposite films. The effects of the DHC content and bleaching treatment via hydrogen peroxide (H2O2) on the tensile and thermal properties of the CS/DHC biocomposite films were investigated. The results showed that the tensile strength and percentage of elongation at break decreased with increasing DHC contents, but the modulus of elasticity of the CS/DHC biocomposite films increased along with the DHC contents. The bleaching treatment of the durian husk is to remove the lignin content to form bleached DHC, resulting in an improvement of tensile strength, modulus of elasticity, and thermal properties of bleached CS/DHC biocomposite films. The functional groups of the unbleached and bleached DHC filler were proved by the Fourier transform infrared (FTIR) analysis, and the thermal stability and glass transition temperature (Tg) of the CS/DHC biocomposite films were measured by the thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) analysis, respectively.
      PubDate: 2017-11-28T00:35:36.876872-05:
      DOI: 10.1002/adv.21921
       
  • Effects of air vents on the flow of reacting polyurethane foam in a
           refrigerator cavity
    • Authors: İ. Bedii Özdemir; Hamed Pahlavani
      Abstract: The transport equations for momentum, enthalpy, and chemical species are solved to simulate the reactive flow of polyurethane foam in a refrigerator cavity. The chemical reactions are described by a mechanism with four reactions and eight species. The numerical findings are also supported by dimensional arguments, which lead to important design attributes. Results prove that the model can be used not only to predict the flow features during the expansion of a multi-component foam, but also to determine the locations and the size of the air vents to avoid air bubbles trapped during the solidification process. It appears that the distribution of the vent holes must be evenly balanced around the cabinet cavity, where the larger holes must be located at positions far from the injector. To prevent the formation of large air voids, which cannot reach the vent holes by the action of gravity, there must be additional holes located on the lower surfaces of the cavity to purge the air trapped.
      PubDate: 2017-11-28T00:30:52.694882-05:
      DOI: 10.1002/adv.21916
       
  • Design high heat-resistant stereocomplex poly(lactide acid) by
           cross-linking and plasticizing
    • Authors: Li Cui; Yahui Wang, Rundong Zhang, Yun Liu
      Abstract: Effects of cross-linking agent (TAIC) and plasticizer (PEG) on stereocomplex-type poly(lactide acid) (sc-PLA) formation and heat resistance properties were conducted. Both homochiral poly(lactide acid) (hc-PLA) and sc-PLA formed in poly(L-lactide acid) (PLLA)/poly(D-lactide acid) (PDLA) blend. After cross-linking, both enthalpy and Tm of hc-PLA or sc-PLA in cross-linked PLLA/PDLA blends all decreased with TAIC content increase. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) analyses indicated that sc-PLA crystallites exclusively formed, without any hc-PLA as the result of the further incorporation of more than 5 phr PEG plasticizer. Heat resistance properties were analyzed through thermogravimetric analysis and vicat softening temperature. Results indicated that chemical cross-linking improved the heat resistance of PLLA/PDLA sample. Moreover, lower concentrations of plasticizer PEG contributed to further improve the heat resistance of cross-linked PLLA/PDLA. The influence of TAIC and PEG on the thermal stability of PLLA/PDLA was also investigated using DSC.
      PubDate: 2017-11-24T10:20:38.186272-05:
      DOI: 10.1002/adv.21917
       
  • Thermal stability, fire behavior, and fumes emission of polyethylene
           nanocomposites with halogen-free fire retardants
    • Authors: Kamila Sałasińska; Monika Borucka, Maciej Celiński, Agnieszka Gajek, Wojciech Zatorski, Kamila Mizera, Milena Leszczyńska, Joanna Ryszkowska
      Abstract: The synergism between nanoparticles and different kinds of halogen-free fire retardants leading to reduction in flammability and smoke generation of polyethylene was investigated. The composites were evaluated by thermogravimetric analysis, oxygen index test, cone calorimeter measurements, and a single-chamber test. Moreover, the semivolatile and volatile compounds evolved in the thermal degradation processes of polyethylene were determined using a steady state tube furnace and gas chromatograph with mass spectrometer. Morphological and structural characteristics as well as thermomechanical properties of the composites were characterized using various techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic mechanical thermal analysis (DMTA). The obtained data were compared to the results received for polyethylene and polymer with bromine-containing fire retardants. The incorporation of nanofillers and halogen-free fire retardants caused a reduction in combustibility as a consequence of the formation of char. Furthermore, the presence of nanoparticles has a beneficial effect on the inhibition of dripping. The polyethylene with carbon nanotubes, zinc borate, and aluminum hydroxide exhibited better combined properties of fire behavior and production of nontoxic smoke compared to the remaining composition and reference materials.
      PubDate: 2017-11-24T06:41:27.581289-05:
      DOI: 10.1002/adv.21914
       
  • Tensile and impact properties of cost-effective hybrid fiber metal
           laminate sandwich structures
    • Authors: Sivakumar Dhar Malingam; Faizal Azli Jumaat, Lin Feng Ng, Kathiravan Subramaniam, Ahmad Fuad Ab Ghani
      Abstract: Hybrid composite materials, which combine two or more types of fiber in a single matrix, have currently drawn the interest of researchers. This research investigates the tensile and impact properties of hybrid kenaf/glass reinforced metal laminates (FMLs) with different fiber orientations and stacking configurations. FMLs were formed by sandwiching the annealed aluminum 5052 sheets to the composite laminates using hot press molding compression technique. The tensile test was performed at a quasi-static rate of 2 mm/min with reference to ASTM E8 whereas Charpy impact test was conducted using impact pendulum tester according to ASTM E23. Results showed that improvement in tensile and impact strength was observed in hybrid FMLs compared to kenaf fiber reinforced FMLs. Fiber orientation of ±45° reduced the tensile strength but increased the impact strength of FMLs in comparison with fiber orientation of 0°/90°. Overall, hybrid FMLs incorporated with a fiber stacking sequence of glass/kenaf/glass showed superior characteristic in tensile and impact performance.
      PubDate: 2017-11-13T00:50:51.148597-05:
      DOI: 10.1002/adv.21913
       
  • Manipulating morphology in thermoplastic protein/polyester blends for
           improved impact strength
    • Authors: Matthew J. Smith; Casparus J. R. Verbeek
      Abstract: Novatein thermoplastic protein was blended with 10 wt% poly(butylene adipate-co-terephthalate) (PBAT) compatibilized with Joncryl ADR-4368 and 2-methylimidazole (2MI). Morphology was tailored for favorable impact strength through changing viscosity ratio (λ) and interfacial tension (γ12). For uncompatibilized blends, λ decreased and γ12 increased with increasing Novatein water content, whereas compatibilizers caused a decrease in both λ and γ12. PBAT continuity was high when uncompatibilized, but dispersion improved with decreasing λ and increasing γ12. The dispersed domain size decreased in all compatibilized blends; PBAT continuity was lowest in samples with the smallest λ. Compatibilized blends had higher impact strength than Novatein and uncompatibilized blends through improved interfacial adhesion, smaller domain size, and increased dispersion. By altering λ and γ12, and with appropriate chemical interaction, a morphology can be created for improved impact strength. Increasing PBAT content showed further increases in impact strength; however, a cocontinuous morphology formed, demonstrating that composition can override the effect of λ and γ12.
      PubDate: 2017-11-13T00:31:03.724118-05:
      DOI: 10.1002/adv.21911
       
  • Chitosan/collagen blends with inorganic and organic additive—A
           review
    • Authors: B. Kaczmarek; A. Sionkowska
      Abstract: This review provides a report on recent studies of composite materials based on a chitosan and collagen mixture due to their biocompatibility and bioactivity. Those natural polymers are most widely used to obtain biomaterials. However, the materials based on chitosan/collagen complexes present poor mechanical parameters, as well as high swelling behavior and enzymatic degradation rate. Such properties are considered problematic for the material clinical application. An increased interest in composite materials has been observed due to their enhanced physicochemical properties. A composite material preparation involves different compounds addition to natural polymers. Herein, the use of organic and inorganic additives has been reported. Moreover, the potential application of composite materials based on chitosan/collagen complexes in the tissue engineering science has been discussed.
      PubDate: 2017-11-09T00:35:54.274059-05:
      DOI: 10.1002/adv.21912
       
  • Prediction of foamability of polyethylene terephthalate using viscous and
           elastic parameters
    • Authors: Zhaoping Yang; Chunling Xin, Waqas Mughal, Zeming Wang, Xue Bai, Yadong He
      Abstract: Rheological behavior and foamability of polyethylene terephthalate (PET) with different molecular structures were investigated. The aim of this study was to find out the viscous and elastic parameters which can predict the foaming properties of PET. It is found that the foams of strain hardening PET have high expansion ratios and fine cell morphologies. This is correlated with the contribution of strain hardening to the improvement of melt strength and failure strain during elongational experiments. Basing on the fact that foamability of a material is governed by its strain hardening (a pure elastic behavior), a viscous parameter (complex viscosity), and an elastic parameter (loss tangent) obtained from dynamic shear rheology are well linked to the expansion ratios of foams. These two parameters formed an optimized viscoelastic window, which is suitable for foaming. This means the foamability of PET can be determined by viscous and elastic parameters without consideration of molecular constitution.
      PubDate: 2017-10-30T23:41:02.712255-05:
      DOI: 10.1002/adv.21910
       
  • Thermal decomposition study of polyvinyl chloride in the presence of
           commercially available oxides catalysts
    • Authors: Jan Nisar; Muhammad Sufaid Khan, Munawar Iqbal, Afzal Shah, Ghulam Ali, Murtaza Sayed, Rafaqat Ali Khan, Faheem Shah, Tariq Mahmood
      Abstract: The pyrolysis behavior of polyvinyl chloride (PVC) in the presence of commercially available oxides catalysts was investigated using thermogravimetry. The pyrolysis proceeded under a heating rate of 5°C/min in the temperature range of 200–650°C. The thermogravimetric properties in terms of reduction in maximum degradation temperature and percent conversion were studied. The silica gel mesoporous catalyst, with a greater pore size and surface area, was found to be the most active materials in terms of reduction in maximum degradation temperature and increase in percent conversion. The alumina acidic, silica ppt, and alumina neutral catalysts also showed good results; however, their effects were less pronounced as compared to silica gel. The effects of these different catalysts show that surface area, pore size, and number of acidic sites are found to be the major factors for the energy efficient degradation of polymers.
      PubDate: 2017-10-23T01:29:21.318465-05:
      DOI: 10.1002/adv.21909
       
  • Supramolecular hydrogel of poly(vinyl alcohol)/chitosan: A dual cross-link
           design
    • Authors: Zheng Zhang; Tingting Li, Yuan Liu, Fang Shang, Bing Chen, Yunxia Hu, Sui Wang, Zhiyong Guo
      Abstract: Supramolecular hydrogels are increasingly fascinating soft polymeric materials formed by noncovalent interactions. Poly(vinyl alcohol) (PVA), chitosan and graphite oxide (GO), good biocompatibility, and nontoxicity, are green materials with potential applications in biomaterials. Herein, a dual cross-link supramolecular hydrogel of PVA/chitosan in the presence of GO was prepared. Without addition of any organic cross-linker, the dual-network PVA/chitosan hydrogel was obtained, namely GO nanosheets as 2D cross-linker and H-bonding between PVA chains. For one thing, GO nanosheets induce the physical network formation through electrostatic interaction between positively charged PVA, chitosan, and negatively charged GO. For another, PVA chains can be connected by H-bonding through freezing/thawing measurements, resulting in the formation of another physical network. To investigate the performance of the PVA/chitosan/GO hydrogel, infrared spectrum, swelling test, thermal analysis, rheological study, and self-healing tests were conducted. The result showed that PVA/chitosan hydrogel in the presence of GO is not only self-healable, but also pH-responsive and temperature-dependent.
      PubDate: 2017-10-23T00:43:09.478494-05:
      DOI: 10.1002/adv.21877
       
  • Toughening of polyamide 12/nanoclay nanocomposites by incompatible
           styrene-butadiene-styrene rubber through tailoring interfacial adhesion
           and fracture mechanism
    • Authors: Ali Naeim Abadi; Hamid Garmabi, Farkhondeh Hemmati
      Abstract: The main drawback of polyamide 12 (PA 12)/nanoclay nanocomposites in their wide range of potential engineering applications known as diminished toughness was overcome using incompatible styrene-butadiene-styrene block copolymer (SBS) rubber. Applying optimal processing parameters for co-rotating twin-screw extrusion resulted in strong interfacial adhesion of matrix and rubber and intercalated and delaminated nanoclay stacks confined in the matrix. The formulation of compatibilized PA 12/SBS/nanoclay nanocomposites was optimized by employing response surface Box–Behnken methodology. A combination of microscopic methods, that is, atomic force microscopy, transmission and scanning electron microscopy, and transmission optical microscopy, along with single-edge-double-notch four-point-bending technique, was exploited to exhaustively explore the toughening mechanisms and microstructure. The findings verify that by tailoring the rubber/matrix interfacial strength and nanocomposite morphology, the Izod impact strength of PA 12/nanoclay nanocomposites is noticeably improved even by incorporating an incompatible rubber and tough fracture mechanisms including rubber particle cavitation and large-scale shear yielding are attained.
      PubDate: 2017-10-17T00:11:10.618641-05:
      DOI: 10.1002/adv.21906
       
  • PAA/alumina composites prepared with different molecular weight polymers
           and utilized as support for nickel-based catalyst
    • Authors: Peng Zhou; Song Wang, ChuanLan Tao, Xingkui Guo, Luhan Hao, Qian Shao, Lei Liu, Ya-Ping Wang, Wei Chu, Bin Wang, Shi-Zhong Luo, Zhanhu Guo
      Abstract: Mesoporous alumina, as a porous, high specific surface area, high activity, and heat stable material, has been widely used as an industrial adsorbent, catalyst, and catalyst support. The modification of alumina with organic polymers has been widely investigated in recent years. In this study, we compared the dependence of the adsorption of a polyelectrolyte, poly(acrylic acid) (PAA) on γ-alumina particles on polymer size via Fourier transform infrared spectroscopy, thermogravimetry, nitrogen adsorption–desorption isotherm analysis, and atomic absorption spectrophotometry. We found that PAA with a hydrodynamic diameter greater than the alumina pore size would only adsorb on the outer surface of the oxides. For polymers with hydrodynamic diameters smaller than the alumina pore size, PAA infiltration resulted in a monolayer coverage of both the outer and inner surfaces of the oxide. Among the three PAA that could infiltrate the alumina pores, the one with the smallest molecular weight showed the highest adsorbed amount on alumina. The temperature, pH, concentration, and ionic strength of the PAA solutions were varied to illustrate the physicochemical differences of the prepared polymer/oxide composite materials. The high PAA-loaded composites were treated with a nickel ion solution, converted to Ni/alumina catalysts, and used in the methanation of carbon dioxide. The Ni/alumina catalysts were analyzed with X-ray diffraction and temperature-programmed reduction to illustrate the structural characteristics. The catalytic CO2 methanation of the catalyst samples revealed that a solution pH value higher than pKa of PAA favored the formation of catalysts with high catalytic activity.
      PubDate: 2017-10-11T00:04:50.157264-05:
      DOI: 10.1002/adv.21908
       
  • Porous wheat gluten microparticles obtained by electrospray: Preparation
           and characterization
    • Authors: José́ A. Tapia-Hernández; Dora E. Rodríguez-Félix, Maribel Plascencia-Jatomea, Agustín Rascón-Chu, Guadalupe A. López-Ahumada, Saúl Ruiz-Cruz, Carlos G. Barreras-Urbina, Francisco Rodríguez-Félix
      Abstract: Currently, microporous polymer materials are being studied extensively due to their attractive properties which allow for a wide potential of applications, such as prolonged-release systems (PRS). The objective of the present work was to prepare and characterize porous microparticles of wheat gluten (WG) using the electrospray technique. The effect of the physicochemical parameters of the solution and electrospray technique parameters on the morphology and size of the materials obtained was studied. For all of the concentrations of WG, porous microparticles with sphere geometry were obtained. At higher concentrations of WG (8% w/v), higher values of viscosity (0.32405 ± 0.002 Pa·s), density (0.997 ± 0.0005 g/cm3), and particle size (1.42 ± 0.71 μm) were obtained, while at lower concentration, high stability rheological is presented, which exhibited Newtonian fluid behavior. Characterization by scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffraction indicated that the material obtained has a potential application in the PRS industry.
      PubDate: 2017-10-10T23:46:07.393281-05:
      DOI: 10.1002/adv.21907
       
  • Mode I interlaminar fracture toughness of carbon-epoxy coupons with
           embedded ceramic sensors
    • Authors: Mauricio Torres; Ricardo A. Tellez, Hilario Hernández, Thierry Camps
      Abstract: This study analyses the mechanical and crack growth behavior of woven carbon fiber reinforced plastics (CPRF) with embedded ceramic sensors. The material studied here is 3K-70-P carbon fiber plain weave with EPOLAM 2015® epoxy resin. The composite is manufactured with vacuum bagging procedure. Later on, the composite Mode I interlaminar fracture toughness (GIC) is calculated by means of double cantilever beam tests (DCB) for two layout configurations [0/90] and [±45] with and without embedded sensors. Results give an initial approach of the fracture behavior of an instrumented composite facing an interlaminar crack. The interlaminar fracture toughness for the instrumented specimens is lower compared to the noninstrumented coupons. The presence of the sensor and its wire connection has a considerable impact on the damage tolerance of the woven composite, where the sensors surroundings seem to be the more likely region to be affected by an interlaminar fracture.
      PubDate: 2017-10-09T09:45:45.297769-05:
      DOI: 10.1002/adv.21905
       
  • The effect of relaxation on the deformation of iPP fiber due to creep
           process
    • Authors: Taha Zaki Nabawy Sokkar; Kermal Ahmed El-Farahaty, Mohammed Ibrahim Raslan, Samar Maher El-Khateep, Ahmed Amin Hamza
      Abstract: In this article, we aim to investigate the effect of relaxation processes on isotactic polypropylene filaments, that is stress relaxation and creep relaxation. In addition, variations of the fiber diameter during creep and relaxation are investigated using laser diffraction technique. Double-image multiple-beam technique and Pluta polarizing interference microscope are used to study the influence of relaxation on necking propagation. Micrographs and interference patterns are given for illustration.
      PubDate: 2017-10-06T02:30:45.824385-05:
      DOI: 10.1002/adv.21879
       
  • Distributive mixing in a corotating twin screw channel using Lagrangian
           particle calculations
    • Authors: Baiping Xu; Huiwen Yu, Lih-Sheng Turng
      Abstract: This work is devoted to the development of a new mapping method for the numerical simulation of melt flow in the complicated forward conveying element of a corotating twin screw extruder under the assumption of periodic boundary conditions of inlet and outlet. The mesh superposition technique (MST) provided by the commercial computational fluid dynamics (CFD) software POLYFLOW was used to deal with the internal moving screw elements, and the flow field of polymer melt obeying the Bird–Carreau constitutive model on the fixed meshes of the flow domain was further solved. After inputting the exported data of the flow field from POLYFLOW, the self-developed code was further used to characterize the mixing behavior at a finite time under different rotation speeds of the screw elements. A novel mapping method was proposed to convert the instantaneous flow field at the initial time point into the velocity field at any time point. Advection evolution of passive particle groups was simulated by a fourth-order Runge–Kutta tracking method, and the corresponding variance index was also calculated. The effect of screw rotation speed on distributive mixing was examined. The results showed that the mixing was highly dependent on the initial position whether the particle groups were first placed close to or far away from the intermeshing zone.
      PubDate: 2017-10-03T23:31:16.973945-05:
      DOI: 10.1002/adv.21880
       
  • Molecularly imprinted polymer membrane for the removal of naphthalene from
           petrochemical wastewater streams
    • Authors: Sahar Ghasemi; Ali Nematollahzadeh
      Abstract: The aim of this work was the preparation of molecularly imprinted membrane (MiM) using polysulfone (PSf) polymer for targeted removal of polycyclic aromatic hydrocarbons from petrochemical wastewater. Naphthalene was opted as a model pollutant, and the imprinted membrane was fabricated by phase inversion technique. Nonimprinted membrane (NiM) was also prepared in the absence of naphthalene and used as a reference. The polymers (MiM/NiM) were systematically characterized using different characterization techniques. The selectivity property of the membranes was evaluated by their ability in separation of naphthalene through filtration tests. Results showed that in comparison with NiM, the imprinted membrane exhibits higher affinity toward naphthalene molecules. It was found that the selectively of MiM is 2.27-fold more than that of the corresponding NiM. This finding can be encouraging from industrial applications points of view.
      PubDate: 2017-09-25T01:06:13.263076-05:
      DOI: 10.1002/adv.21904
       
  • Wear performance of multiwalled carbon nanotube-reinforced ultra-high
           molecular weight polyethylene composite
    • Authors: Nayeli Camacho; Edgar A. Franco-Urquiza, Stephen W. Stafford
      Abstract: Ultra-high molecular weight polyethylene (UHMWPE) has proven to be a good counterpart articulating surface against Cr–Co–Mo femoral components in artificial joints. Nevertheless, UHMWPE wear damage and subsequent aseptic loosening continues to be the main reason for revision of knee replacements. There is an ongoing research effort to improve the metal-on-UHMWPE couple. This study compares the wear resistance of multiwalled carbon nanotube-reinforced UHMWPE composite with conventional orthopedic grade UHMWPE currently used in total knee replacements. Defined by previous studies, 1.25 wt.% multiwall carbon nanotubes (MWCNT) were incorporated into UHMWPE to fabricate UHMWPE-MWCNT composites by solution blending, achieving an even distribution in the polymeric matrix. UHMWPE-MWCNT samples were manufactured by compression molding and sterilized with γ-rays. Scanning electron microscopy confirmed a uniform distribution of the MWCNTs. The volumetric wear was reduced by 86.9%, and the indentation depth in creep testing decreased 68%. The composite displayed superior wear behavior producing less wear debris than conventional materials.
      PubDate: 2017-09-17T23:55:45.753836-05:
      DOI: 10.1002/adv.21885
       
  • The evaluation of stretchability and its applications for biaxially
           oriented polypropylene film
    • Authors: Toshitaka Kanai; Kentaro Egoshi, Satoshi Ohno, Tomoaki Takebe
      Abstract: In recent years, plastic film is essential in our daily lives. Among them, polypropylene has good physical properties, for example, tensile strength, impact strength, and transparency. Recently, it was found that the stretchability of polypropylene (PP) is improved by blending a small amount of low modulus polypropylene (LMPP) which is a low tacticity polypropylene. The purpose of this research was to investigate the effect of blending LMPP, which has different characteristic of resin such as tacticity and molecular weight, on PP and to study the mechanism of the structure formation in a biaxial stretching process. The blending of LMPP to PP reduces the spherulite size and increases the thickness of the amorphous phase in the lamella without changing the thickness of the crystal phase, namely the melting temperature. LMPP blends also reduced the yield stress during the stretching process and increased the stress buildup ratio. For these reasons, it improved film thickness uniformity of biaxially stretched film and reduced film break during the high production line. Furthermore, as the stretchable temperature window was widened to the low-temperature side, the thickness uniformity was improved in the wide stretchable temperature. As a result, improving the stretchability and the film thickness uniformity of PP were achieved by blending LMPP to PP.
      PubDate: 2017-09-17T23:46:45.225089-05:
      DOI: 10.1002/adv.21884
       
  • A study of dielectric behavior of manganese doped barium
           titanate–polyimide composites
    • Authors: Anuradha Kumari; Barnali Dasgupta Ghosh
      Abstract: In this work, a series of BaTi1−xMnxO3–polyimide films were prepared by simple solution casting method. For the preparation of composite films firstly, manganese doped barium titanate, BaTi1−xMnxO3 (where x = 0.00, 0.01, 0.03, 0.05) was synthesized by sol-gel process. The effect of Mn doping on its structural and dielectric properties was nicely explained. The highest dielectric constant value of 7,104 was obtained for BaTi0.99Mn0.01O3 (BTMn) nanoparticles with low dielectric loss value 2.44. It was observed that Mn-doping concentration on barium titanate influences its crystal structure. Improved dielectric properties were reported for nanocomposite thin films containing BaTi0.99Mn0.01O3 and polyimide (PI). A series of five homogeneous nanocomposite films were successfully prepared and were characterized thoroughly. The dielectric properties were studied as a function of frequency and loading percentage of BTMn in PI. The dielectric constant of the BTMn/PI nanocomposite films increased from 3.23 to 8.63 with the increase in loading percentage of ceramic from 0 to 5 wt%, respectively. The nanocomposite films were flexible with good mechanical properties and the flexibility decreased with increase in loading percentage of BTMn. The films showed high thermal stability in nitrogen atmosphere up to 571°C with 10% weight loss and also exhibited high glass transition temperature up to 337°C.
      PubDate: 2017-09-15T22:36:22.355759-05:
      DOI: 10.1002/adv.21886
       
  • Influence of filler loading and palm oil-based green coupling agent on
           torque rheological properties of polypropylene/cocoa pod husk composites
    • Authors: Seong Chun Koay; Ming Yeng Chan, Ming Meng Pang, Kim Yeow Tshai
      Abstract: This research examined the torque rheological properties of cocoa pod husk (CPH)-filled polypropylene (PP) composites. Composites with varying filler loading ranging from 10 to 40 phr and formulation with or without palm oil-based green coupling agent (GCA-P) were analyzed using a Brabender Plastrograph torque rheometer. The GCA-P synthesized from fatty acid of palm oil was used to enhance adhesion at the filler–matrix surface interfaces. The results reveal that PP/CPH composites containing 40 phr filler loading and GCA-P exhibited higher processing torque and power law index (n). Higher melt viscosity was recorded at higher filler loading, owning to filler agglomeration and more effective filler-matrix adhesion in the presence of GCA-P. As a result, higher energy was required to compound PP/CPH composites, which could be attributed to the increase in activation energy (Ea) at higher melt viscosity.
      PubDate: 2017-09-14T04:41:59.899858-05:
      DOI: 10.1002/adv.21883
       
  • The influence of hydrophilic mPEG segment on formation, morphology, and
           properties of PCL-mPEG microspheres
    • Authors: Yu He; Ping Liu, Chen Shi, Yongwei Liu, Songxiang Liu, Xiaobo Feng, Dehao Fu
      Abstract: This research displayed the differences of formation process, morphology, degradation, and release behaviors between PCL and PCL-mPEG microspheres. Lysozyme loaded microspheres were prepared by double emulsion evaporation method, and the double droplets transformation process was observed and compared under microscope. Microspheres morphology, in vitro degradation and release behaviors were evaluated by scanning electron microscope, gel permeation chromatography, and bicinchoninic acid protein assay kit. PCL-mPEG microspheres got a rough surface and the outer water phase penetrated into PCL-mPEG double droplet easier than PCL during the transformation, accompanied with a high broken percentage and size swelling. PCL-mPEG microspheres get a faster degradation/erosion rate than PCL microspheres, and the rate was in direct proportion to mPEG chain length. In vitro release analysis showed that PCL-mPEG microspheres get a faster release rate than PCL microspheres, and the rate was also in direct proportion to mPEG chain length.
      PubDate: 2017-09-14T02:08:25.63454-05:0
      DOI: 10.1002/adv.21887
       
  • Electrochemical co-deposition and characterization of polyaniline and
           manganese oxide nanofibrous composites for energy storage properties
    • Authors: Anwar-ul-Haq Ali Shah; Muhammad Owais Khan, Salma Bilal, Gul Rahman, Hung Van Hoang
      Abstract: Ion diffusion rate and contact surface area of conducting polymers increased by composite formation with nanometric-size materials make them promising materials in the fabrication of energy storage devices. In this work, electronically conducting polyaniline and manganese oxide (PANI/MnO2) nanofibrous composites were electrochemically co-deposited on stainless steel from binder-free electrolyte solution. Structural characterization and morphological characterization of the materials were performed with Fourier-transformed infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). SEM images show fibrous micro/nano-architecture of the composites with cluster networking structure having 200–500 nm length and 100–200 nm diameter. Electrochemical and energy storage properties of the as-synthesized materials were investigated with cyclic voltammetry (CV), galvanostatic charge discharge curves(GCDC), and potentiostatic electrochemical impedance spectroscopy (PEIS) without any binders. Electrochemical measurements as well as galvanostatic charge discharge curves at 1 mA constant current have shown maximum specific capacitance of 149 F/g for the composite prepared with 0.15 M MnSO4 in the co-deposition bath. The composites retain 67% specific capacitance even after 400 cycles, indicating the stability of synthesized composite. PEIS confirms the pseudocapacitive nature of the synthesized composites.
      PubDate: 2017-09-05T00:45:54.060941-05:
      DOI: 10.1002/adv.21881
       
  • Effects of carbon black content and size on conductive properties of
           filled high-density polyethylene composites
    • Authors: Ji-Zhao Liang; Quan-Quan Yang
      Abstract: The high-density polyethylene (HDPE) composites filled with four kinds of carbon blacks (CB) were prepared to investigate the effects of the size and content of the CB on the electrical properties of the HDPE/CB composites. It was found that the composites presented conductive percolation behavior, the CB with different size filled-systems had different percolation thresholds; the higher the structure property of the CB, the larger the particle surface area, and the smaller the particle size, the better was the conductivity, and the lower was the percolation threshold of the composites. In addition, the HDPE/CB composites showed significant positive temperature coefficient (PTC) effect and negative temperature coefficient effect. The bigger the filler particle diameter, the higher was the PTC intensity of the HDPE composite systems under the same CB weight fraction.
      PubDate: 2017-09-04T04:51:00.32273-05:0
      DOI: 10.1002/adv.21882
       
  • Preparation and characterization of starch nanocomposite embedded with
           functionalized MWCNT: Investigation of optical, morphological, thermal,
           and copper ions adsorption properties
    • Authors: Shadpour Mallakpour; Ahmadreza Nezamzadeh Ezhieh
      Abstract: The purpose of this research was to fabricate starch nanocomposites (NC)s using corn starch and MWCNTs-Valine as efficient fillers, and to examine the impact of nanofillers on the starch's properties. At first, Valine was grafted onto the MWCNTs' surfaces through a chemical reaction. Then, the functionalized MWCNTs (0.5, 1, and 2 wt.%) were embedded in the starch by ultrasonic technique. The field emission scanning electron microscopy showed homogeneous distribution of nanofillers in the starch matrix. Moreover, thermogravimetric analysis demonstrated that the starch's thermal stability was improved after addition of MWCNTs. Finally, the adsorption behavior of the prepared NC for the elimination of copper ions from the aqueous solution was investigated.
      PubDate: 2017-09-04T04:06:31.910614-05:
      DOI: 10.1002/adv.21878
       
  • Hydroxypropyl-β-cyclodextrin hybrid nanogels as nano-drug delivery
           carriers to enhance the solubility of dexibuprofen: Characterization, in
           vitro release, and acute oral toxicity studies
    • Authors: Qandeel Khalid; Mahmood Ahmad, Muhammad Usman Minhas
      Abstract: The purpose of this study was to develop and characterize hydroxypropyl-β-cyclodextrin (HPβCD) hybrid nanogels for solubility enhancement of lipophilic drug, dexibuprofen. HPβCD hybrid nanogels were designed by chemical cross-linking of hydroxypropyl-β-cyclodextrin with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) via free radical polymerization. Loading efficiency, solubilization, zetasizer, FESEM Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD), and in vitro drug release analysis were performed for characterization of hybrid nanogels. Efficient solubilization of dexibuprofen has been observed by HPβCD hybrid nanogels. FTIR, TGA, and DSC studies confirmed the formation of new hybrid nanogels and complexation of dexibuprofen with nanogels. XRD analysis revealed loss of dexibuprofen crystallinity in hybrid nanogels. Highly porous and amorphous nanogels showed a significant dexibuprofen release in aqueous medium. In toxicity studies, no significant changes in behavioral, physiological, biochemical, or histopathological parameters of animals endorsed that developed formulations are nontoxic and biocompatible.
      PubDate: 2017-09-04T03:55:53.704874-05:
      DOI: 10.1002/adv.21876
       
  • Improvements in mechanical strength and thermal stability of injection and
           compression molded components based on Poly Lactic Acids
    • Authors: Clizia Aversa; Massimiliano Barletta, Annamaria Gisario, Elisa Pizzi, Michela Puopolo, Silvia Vesco
      Abstract: Degradable polymers are limited by their often-insufficient mechanical and thermal properties, which limit their usage to single-use packaging items at room temperature and in dry conditions. In this respect, the present work deals with the manufacture of custom-built Poly Lactic Acids (PLAs), which are designed to be compostable, suitable for food contact and are characterized by a good compromise between mechanical properties and thermal stability. A commercial grade PLA was, therefore, compounded in a twin-screw co-rotating extruder by the use of specific additives: maleated and glycidyl methacrylate PLAs as compatibilizers/chain extenders and microlamellar talc as mineral filler/nucleation promoter. After pelletizing, the resulting compounds were melt-processed by injection and compression molding. Differential scanning calorimetry, flexural tests in static machine and top-hat cylindrical flat indentations were performed to evaluate the thermal and mechanical response of the molded components. The experimental findings show that crystallization of the PLA can be controlled by fine-tuning the compound formulation as well as by properly setting the processing parameters. In addition, achievement of the appropriate crystallization degree in the polymer can lead to molded components, which exhibit improved mechanical strength and high thermal stability.
      PubDate: 2017-08-18T00:20:47.143611-05:
      DOI: 10.1002/adv.21875
       
  • Synthesis and surface properties of a novel fluorine modified acrylate
           colloid
    • Authors: Xiuming Wang; Tingting Xu, Cuifeng Zhang, Lijun Chen
      Abstract: The novel modified acrylate colloid was synthesized by semi-continuous seeded emulsion polymerization which was initiated with potassium persulfate (KPS), and octylphenol polyoxyethylene ether (OP-10) and sodium dodecyl benzene sulfonate (SDBS) were used as surfactants. Butyl acrylate (BA) and methyl methacrylate (MMA) were used as the main monomers and hexafluorobutyl methacrylate (HFMA, C8H8F6O2), and benzyl methacrylate (BZMA, C11H12O2) were used as functional monomers. Factors such as the amount of initiator, mass ratio of SDBD to OP-10 and monomers, which have an influence on particle size and morphology of the resultant colloid, are studied. Chemical composition of the modified acrylate colloid was evaluated by Fourier transform infrared spectrometry (FTIR). The thermal performances were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). Furthermore, surface hydrophobicity of the latex film was examined by measurement of water absorption and water contact angle. Results indicate that the modified acrylate colloid has highest monomer conversion rate and lowest coagulation percentage when the mass fraction of emulsifier was 4% and mass ratio of SDBS to OP-10 was 1:2, mass fraction of initiator was 0.3%, mass percent of HFMA was 6%, and the amount of BZMA was 2%. Benzene ring-containing monomer is effectively participated in the reaction and has improved the thermal performance and surface properties of copolymer colloid. The resultant colloid has excellent hydrophobicity and low surface energy. Solid content of the resultant colloid was about 30% (wt %).
      PubDate: 2017-08-18T00:00:48.148969-05:
      DOI: 10.1002/adv.21874
       
  • A computer model for starve-fed single-screw extrusion of polymer blends
    • Authors: Krzysztof J. Wilczyński; Andrzej Nastaj, Krzysztof Wilczyński
      Abstract: A new computer model has been developed to simulate a starve-fed single-screw extrusion process of polymer blends. This is a composite model, which is based on combining melt conveying models with new fusion models for polymer blends. The model is able to predict pressure and temperature profiles, filling of the screw and rate of polyblend fusion. Computer calculations were executed for extrusion of high-density polyethylene and polystyrene blend at various technological conditions, and fill factor, pressure, temperature, and fusion profiles were calculated. The results of simulation studies were verified by experiment.
      PubDate: 2017-08-11T00:15:51.70099-05:0
      DOI: 10.1002/adv.21873
       
  • Analysis of structural changes in injection-molded parts due to cyclic
           loading
    • Authors: Elzbieta Bociaga; Monika Kula, Konrad Kwiatkowski
      Abstract: The investigations of the change in properties and structure of polypropylene injection-molded parts, arising from cyclic loading, are presented. The strain–stress characteristics were determined in the cyclic tensile tests, at a fixed stress or deformation level. Experiments showed that cyclic loading causes some changes in structure and mechanical properties of polypropylene samples. Smaller total strain of samples and increase in Young's modulus after each consecutive ten cycles of loading were observed as the result of loading at a fixed stress level. In experiments carried out at the fixed strain level, the width of the loop decreases with the increase in number of cycles that indicates the material strengthening. Microscopic examinations showed the change in the structure of injection-molded parts after cyclic loading. The transient zone, occurring in the area of high shear stress between the core and the skin, became significantly wider for cyclically loaded parts. Phase changes in the part structure were investigated using WAXS method. Samples exhibited the difference in the content of polypropylene polymorphic modifications between the core and skin layers. In the skin, both for nonloaded and loaded parts, the presence of β-phase was confirmed, whereas this phase did not occur in the core. The investigation by DSC method demonstrated a small change in the degree of crystallinity in the sample core after 4,000 cycles of loading, while in the skin layer, the degree of crystallinity was reduced by about 2% when compared to the value obtained for samples after one loading cycle.
      PubDate: 2017-07-31T07:21:33.375237-05:
      DOI: 10.1002/adv.21872
       
  • Modeling and optimization of electrospinning of polyvinyl alcohol (PVA)
    • Authors: Mohamed Elkasaby; Hussien A. Hegab, Atef Mohany, Ghaus M. Rizvi
      Abstract: The electrospun fibers can have applications in diverse fields, such as tissue scaffolds, optical electronics, nanocatalysis, and sound absorption. Nanoscale fibers with a higher surface area can provide superior mechanical, physical, and thermal properties. Therefore, investigation of the factors affecting the electrospinning process, for various materials, is required. In this study, the design of experiments issued for optimization of electrospinning of polyvinyl alcohol (PVA). Analysis of variance (ANOVA) and the Taguchi orthogonal array L27OA are employed to analyze the influence of process control parameters. The variables studied are the applied voltages, solution concentrations, rotational speeds, collecting distances, and flow rates. A mathematical model of the polymer fiber diameter as a function of significant process parameters has been built using response surface methodology (RSM). The concentration percentage and the flow rate were determined to be the most significant process variables at 99% and 90% confidence levels, respectively. The predictive model provides 84.34% average model accuracy, which is considered acceptable as this study deals only with 27 of 243 trials needed for a full study based on principles of design of experiments. An additional ANOVA test and corresponding mathematical model have been developed to obtain the interaction effects for processing parameters.
      PubDate: 2017-07-24T01:11:01.967078-05:
      DOI: 10.1002/adv.21869
       
  • In situ preparation of chitosan/gold nanocomposite: Structural and
           catalytic properties
    • Authors: Wael H. Eisa; Tarob Abdelnaby, Shahenda Mostafa, Mohamed Y. Elzayat
      Abstract: Chitosan-stabilized gold nanoparticles (Cs/Au) film was prepared by casting strategy without a need for reducing and/or stabilizing agents. The shape, size, and crystalline phase were studied using UV-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The nature of the interaction between the Cs and Au nanoparticles was studied using the Fourier transformer infrared (FTIR) spectroscopy. The as-prepared Cs/Au nanocomposite film showed high activity in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of an excess amount of NaBH4. Furthermore, the Cs/Au film is easily separable, as well as remains active after reused for 3 times. The Cs/Au nanocomposite film could be a promising candidate for various catalytic reactions.
      PubDate: 2017-07-24T01:06:31.935048-05:
      DOI: 10.1002/adv.21867
       
  • pH stimuli-responsive poly(acrylamide-co-sodium alginate) hydrogels
           prepared by γ-radiation for improved compressive strength of concrete
    • Authors: Mohamed Mohamady Ghobashy; Ghada Bassioni
      Abstract: Cross-linking of superabsorbent hydrogels based on poly(acrylamide-co-sodium alginate) is carried out using 60Co γ-radiation. Hydrogels of PAM/NaAlg with 1.5:0.5 and 1.0:1.0 w/v concentrations showed good gel contents of 87 and 66 (%) and swelling degrees in water of 3.7 and 5 (g/g) after 40 min, respectively. The chemical structure of the hydrogel is confirmed by FTIR, XRD, and ESR. The morphology of the hydrogel is observed using scanning electron microscopy. Intramolecular H-bonding in the hydrogel network is confirmed by TGA and DSC. The pH-responsive swelling behavior of (PAM-co-NaAlg) hydrogels is tested in different pH ranges showing higher swelling capacities in basic than in acidic media. This property proposes the use of (PAM-co-NaAlg) hydrogel as internal curing agent for concrete. The hydrogel is examined with cement weight ratios of (0.1–0.5) wt%. The study shows that cement with (PAM-co-NaAlg) hydrogel improves the compressive strength of cement at 0.1 and 0.2 wt%.
      PubDate: 2017-07-20T00:26:37.158011-05:
      DOI: 10.1002/adv.21870
       
  • Effectiveness of different kinds of antioxidants in resin-cured bromobutyl
           rubber vulcanizates
    • Authors: Na Lu; Mei Shen, Zhanfeng Hou, Prakashan K, Zhenxiang Xin
      Abstract: Antioxidants are customarily used in elastomer compounds to enhance the service life of vulcanizates enduring high temperatures, but proper selection and dosage of the antioxidant is critical to obtain maximum beneficial effect. In this study, the effectiveness of several commercially available antioxidants on the performance of a resin-cured bromobutyl rubber (BIIR) vulcanizate was investigated. The antioxidants investigated belonged to different chemical classes such as p-phenylene diamine (antioxidant 4010NA), secondary amine (antioxidant 445), quinoline (antioxidant RD), and phenolic (antioxidants BHT, 1010, and 2246). The physicomechanical properties of the BIIR vulcanizates containing the various antioxidants were tested at room temperature, at higher temperatures, after subjecting to heat aging, and after storage. The results show that the physicomechanical properties of the BIIR vulcanizate severely deteriorate when antioxidant 4010NA is used. Among the other antioxidants used, the phenolic-type antioxidant BHT is found to be better for the resin-cured BIIR vulcanizate of this study.
      PubDate: 2017-07-18T22:45:30.183165-05:
      DOI: 10.1002/adv.21865
       
  • Theoretical analysis of the spunbond process and its applications for
           polypropylenes
    • Authors: Toshitaka Kanai; Youhei Kohri, Tomoaki Takebe
      Abstract: The theoretical analysis of the spunbond process was set up and applied to polypropylene (PP) and its blends. The effect of blending low tacticity polypropylene (LMPP) to high tacticity PP on the spinnability of the spunbond process was investigated. A small amount of LMPP was found to stabilize the high-speed spinning of PP, and very fine fibers were obtained. From the calculated results, it was speculated that the improvement of spinnability originated from the suppression of crystallization speed and strain rate in the spinning process. The physical properties of the spunbond nonwoven fabrics were also investigated.
      PubDate: 2017-07-17T00:40:56.020405-05:
      DOI: 10.1002/adv.21866
       
  • Processability and mechanical properties of bioplastics produced from
           decoloured bloodmeal
    • Authors: Casparus Johannes Reinhard Verbeek; Aaron Low, Mark Christopher Lay, Talia Maree Hicks
      Abstract: Bloodmeal is a protein-rich coproduct of the meat industry and can be converted into a thermoplastic. A solution of peracetic acid can be used to degrade colored compounds in bloodmeal, yielding a light yellow material. This causes an increase in β-sheets in the protein's secondary structure, but the addition of sodium dodecyl sulfate (SDS) and triethylene glycol (TEG) reduced α-helical and β-sheet content, thereby increasing random coils. Without SDS, chains were less capable of folding into these structures, preventing sufficient intermolecular interactions and chain entanglement, leading to low specific mechanical energy input (SME) during extrusion, and poor consolidation. The whiteness of molded samples showed no correlation with SME during extrusion or the degree of consolidation after extrusion; however, they were observed to have a higher level of whiteness with increasing TEG content and should be considered as a secondary process not directly linked to extrusion. Increasing the amount of water during extrusion increased the Young's modulus (E) by facilitating formation of new interactions, while increasing TEG decreased E as a result of plasticization. The action of SDS on destabilizing electrostatic and hydrophobic interactions was beneficial to extrusion, although it had no further effect during injection molding. TEG had virtually no effect on tensile strength, although it was required for flow and facilitated the formation of strong interactions after water had been evaporated during conditioning.
      PubDate: 2017-07-16T23:00:38.071287-05:
      DOI: 10.1002/adv.21868
       
  • Biosourced blends based on poly (lactic acid) and polyamide 11:
           Structure–properties relationships and enhancement of film blowing
           processability
    • Authors: Fatma Walha; Khalid Lamnawar, Abderrahim Maazouz, Mohamed Jaziri
      Abstract: The purpose of the present work is to develop a new biomaterial with suitable melt strength, stiffness-to-toughness balance, and the required thermal performance for food packaging applications. The study is dedicated to investigating a new physical compatibilization approach of biosourced materials as well poly (lactic acid) (PLA) and polyamide 11 (PA11) in comparison with the chemical compatibilization through addition of a multifunctionalized epoxide. For this reason, this paper deals with gaining better understanding physical compatibilization in the biosourced blend with the incorporation of an acrylic melt strength enhancer into PLA/PA11 blend. The main focus of this paper is studying how physical compatibilization improves melt strength in comparison with chemical approach. Hitherto, the chain extension–branching balance was demonstrated to be difficult to be controlled and decoupled from chemical compatibilization at the polymer–polymer interface. Hence, the physical approach is presented as an original route in this work to develop a PLA-based blend with good film blown processability and engineering properties. Morphological, rheological and thermomechanical properties of the new obtained biosourced blends were studied. The physical compatibilization effect was confirmed by the tuning interfacial properties. The extensional rheology highlighted that melt strength for the physical blends was also improved without any pronounced strain hardening in comparison with reactive blends. Besides, a great enhancement of the blowing processing windows of physically PLA-PA11 compatibilized blend was highlighted while higher blow-up ratio and take-up ratio values were obtained. Overall, a correlation between the obtained thermal and crystalline properties was performed for the optimal biosourced blown film.
      PubDate: 2017-07-12T23:30:45.0946-05:00
      DOI: 10.1002/adv.21864
       
  • Mechanical recycling simulation of polylactide using a chain extender
    • Authors: Marina Fernandes Cosate de Andrade; Gustavo Fonseca, Ana Rita Morales, Lucia Helena Innocentini Mei
      Abstract: This work studied the commercial chain extender effectiveness on the mechanical recycling simulation of a pristine PLA using a single-screw extruder. We processed the material by two extrusion cycles to simulate a recycling process. In the second extrusion, part of the material was processed with chain extender and we evaluated its molecular weight, thermal degradation, melt flow index (MFI), thermal transitions, and mechanical properties. The molecular weight for the extruded neat PLA decreased and the MFI and crystallinity degree increased while the mechanical properties worsened. The onset thermal degradation occurred at lower temperature for the processed material. With the introduction of the chain extender, there was a recovery of properties with the increase in the polymer molecular weight, decrease in the MFI and crystallinity degree, and an improvement in both thermal stability and mechanical properties in relation to recycled PLA without this component.
      PubDate: 2017-07-12T03:45:38.149453-05:
      DOI: 10.1002/adv.21863
       
  • Application of tree biochar in PDMS pervaporation membranes
    • Authors: Yongqiang Lan; Weihong Wang
      Abstract: In this study, three kinds of biomass materials (lodgepole pine bark, larch wood, larch bark) were used to prepare biochar (BB), and the prepared products as fillers were mixed with polydimethylsiloxane (PDMS) for preparing composite membranes which were used for separating ethanol from water by pervaporation (PV). In accordance with the experiment results, the lodgepole pine bark BB was the best filler for the selective membrane to ethanol. The silane coupling agents NH2(CH2)3Si(OC2H5)3 (KH-550) and CH2=CH-Si(OCH3)3 (YDH-171) were applied in the modification of lodgepole pine bark BB. And the separation performances of the BB/PDMS composite membranes were researched in detail. The results showed that the permeability (flux and separation factor) of composite membranes has been significantly improved with the addition of modified BB. YDH-171 was more effective than KH-550. The optimum PV performances (the separation factor 11.3 and the corresponding flux 227.25 g m−2 h−1) were obtained by adding 3 wt. % modified BB for a 10 wt. % and 40°C ethanol solution. This study indicated the potential application of BB nanoparticles in preparing pervaporation separation membrane.
      PubDate: 2017-07-10T01:22:52.591814-05:
      DOI: 10.1002/adv.21856
       
  • Chitosan phthalate: A novel polymer for the multiparticulate drug delivery
           system for diclofenac sodium
    • Authors: Dasari Subramaniyam Karuna; Grace Rathnam, Udhumansha Ubaidulla, Mani Ganesh, Hyun Tae Jang
      Abstract: This study investigates the preparation of colon specific drug delivery of diclofenac sodium (DS) using maltiparticulate system with chitosan phthalate (CP). Technique adopted to prepare sphere shaped multiparticulate system was extrusion and spheronization. The prepared pellets resulted with good spherical geometry with 1.1 ± 0.20 mm diameter. DS loaded system shows a maximum delivery pH of 7.4 and the same depressed at pH 1.2. The developed system significantly (p 
      PubDate: 2017-07-08T02:35:34.66718-05:0
      DOI: 10.1002/adv.21859
       
  • Synthesis, optimization, and characterization of poly
           (Styrene-co-Acrylonitrile) copolymer prepared via precipitation
           polymerization
    • Authors: Mohamed R. El-Aassar; Mamdouh S. Masoud, Marwa F. Elkady, Ahmed A. Elzain
      Abstract: Poly (Styrene-co-Acrylonitrile) (poly (St-co-AN) copolymer nanoparticles with controllable size are synthesized by a simple and cheap precipitation polymerization technique of styrene (St) and acrylonitrile (AN) monomers in aqueous medium using potassium persulfate (KPS) redox initiation system. Preparation of poly (St-co-AN) and studying all the parameters affecting the polymerization process such as time, temperature, monomer ratio, initiator molarity, cosolvent ratio, and solvent were considered. The resultant poly (St-co-AN) was compared with other studies which used different comonomers with AN, the comparison was assessed by evaluating the polymer conversion yield side. Maximum polymerization conversion yield, 66.5%, was obtained with St:AN (30%:70%) comonomer ratio. The smallest particle size obtained with this method was close to 16.17 nm and controlled by variation in polymerization conditions. The structure of poly (St-co-AN) copolymers were confirmed by Fourier transform infrared (FTIR), thermo gravimetric analysis (TGA), and differential thermal analyzer (DTA). The morphological structure of the copolymer particles was indicated by scanning electron microscope (SEM) photographs. The polymeric particle size was studied using particle size analyzer.
      PubDate: 2017-07-03T23:30:54.366179-05:
      DOI: 10.1002/adv.21860
       
  • Issue Information
    • Pages: 397 - 400
      PubDate: 2017-10-13T06:47:48.921725-05:
      DOI: 10.1002/adv.21769
       
  • News from the Polymer Processing Institute
    • Pages: 525 - 528
      PubDate: 2017-10-13T06:47:49.270486-05:
      DOI: 10.1002/adv.21768
       
 
 
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