Publisher: SciELO   (Total: 893 journals)

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Showing 201 - 400 of 893 Journals sorted alphabetically
Cubo. A Mathematical J.     Open Access  
Cuestiones Constitucionales     Open Access   (Followers: 2, SJR: 0.1, CiteScore: 0)
Cuicuilco     Open Access   (Followers: 1)
Cuicuilco. Revista de Ciencias Antropológicas     Open Access   (Followers: 2)
Cultivos Tropicales     Open Access   (Followers: 1)
Cultura y Representaciones Sociales     Open Access   (Followers: 2)
Culturales     Open Access   (Followers: 3)
Dados - Revista de Ciências Sociais     Open Access   (SJR: 0.37, CiteScore: 0)
De Jure     Open Access   (Followers: 1)
DELTA : Documentação de Estudos em Lingüística Teórica e Aplicada     Open Access   (SJR: 0.133, CiteScore: 0)
Dementia & Neuropsychologia     Open Access   (Followers: 10, SJR: 0.205, CiteScore: 0)
Dental Press J. of Orthodontics     Open Access   (Followers: 5, SJR: 0.489, CiteScore: 1)
Desacatos     Open Access   (Followers: 1)
Desacatos : Revista de Antropología Social     Open Access   (Followers: 2)
Desarrollo y Sociedad     Open Access   (Followers: 3, SJR: 0.109, CiteScore: 0)
Diálogo Andino - Revista de Historia, Geografía y Cultura Andina     Open Access   (Followers: 1, SJR: 0.116, CiteScore: 0)
Diánoia     Open Access   (Followers: 1)
Dimensión Empresarial     Open Access  
Discusiones Filosóficas     Open Access   (Followers: 2)
Dynamis : Acta Hispanica ad Medicinae Scientiarumque Historiam Illustrandam     Open Access   (Followers: 3, SJR: 0.131, CiteScore: 0)
e-J. of Portuguese History     Open Access   (Followers: 2, SJR: 0.101, CiteScore: 0)
e-Pública : Revista Eletrónica de Direito Público     Open Access   (Followers: 2)
Earth Sciences Research J.     Open Access   (Followers: 2)
Eclética Química     Open Access   (Followers: 1)
Ecología en Bolivia     Open Access  
Economia Aplicada     Open Access   (SJR: 0.208, CiteScore: 0)
Economia e Sociedade     Open Access  
EconoQuantum     Open Access  
Educação & Sociedade     Open Access   (Followers: 3)
Educação e Pesquisa     Open Access   (Followers: 1, SJR: 0.163, CiteScore: 0)
Educação em Revista     Open Access  
Educación Matemática     Open Access  
Educación Médica     Open Access   (Followers: 1, SJR: 0.236, CiteScore: 0)
Educación Médica Superior     Open Access   (Followers: 1, SJR: 0.237, CiteScore: 0)
Educación y Educadores     Open Access  
Educar em Revista     Open Access  
EDUMECENTRO     Open Access  
Eidos     Open Access   (SJR: 0.119, CiteScore: 0)
En-Claves del pensamiento     Open Access   (Followers: 1, SJR: 0.194, CiteScore: 0)
Encuentros     Open Access  
Ene : Revista de Enfermería     Open Access  
Enfermería Global     Open Access   (Followers: 3, SJR: 0.165, CiteScore: 0)
Enfermería Nefrológica     Open Access   (Followers: 1, SJR: 0.198, CiteScore: 0)
Enfoques     Open Access  
Engenharia Agrícola     Open Access   (SJR: 0.305, CiteScore: 1)
Engenharia Sanitaria e Ambiental     Open Access   (SJR: 0.218, CiteScore: 0)
Ensaio Avaliação e Políticas Públicas em Educação     Open Access   (Followers: 1, SJR: 0.254, CiteScore: 0)
Ensayos de Economía     Open Access   (Followers: 2)
Ensayos Revista de Economía     Open Access   (Followers: 2)
Entomologia y Vectores     Open Access   (Followers: 2)
Entre Ciencia e Ingeniería     Open Access   (Followers: 2)
Epidemiologia e Serviços de Saúde     Open Access  
Escritos de Psicología : Psychological Writings     Open Access   (Followers: 2)
Estudios Atacameños     Open Access   (Followers: 2, SJR: 0.446, CiteScore: 1)
Estudios Constitucionales     Open Access   (Followers: 5, SJR: 0.319, CiteScore: 0)
Estudios de Cultura Maya     Open Access   (Followers: 2, SJR: 0.272, CiteScore: 0)
Estudios de Economía     Open Access   (SJR: 0.121, CiteScore: 0)
Estudios de historia moderna y contemporánea de México     Open Access   (SJR: 0.101, CiteScore: 0)
Estudios Economicos     Open Access  
Estudios Filologicos     Open Access   (SJR: 0.107, CiteScore: 0)
Estudios Fronterizos     Open Access   (Followers: 1)
Estudios internacionales     Open Access   (Followers: 5)
Estudios Pedagogicos (Valdivia)     Open Access   (Followers: 1, SJR: 0.338, CiteScore: 0)
Estudios Políticos     Open Access  
Estudios Sociales     Open Access   (Followers: 2)
Estudios sociales : Revista de alimentación contemporánea y desarrollo regional     Open Access   (Followers: 2)
Estudios Socioterritoriales : Revista de Geografía     Open Access  
Estudos Afro-Asiáticos     Open Access   (Followers: 2)
Estudos Avançados     Open Access   (SJR: 0.232, CiteScore: 0)
Estudos de Psicologia (Campinas)     Open Access   (Followers: 1, SJR: 0.233, CiteScore: 0)
Estudos de Psicologia (Natal)     Open Access   (SJR: 0.117, CiteScore: 0)
Estudos Econômicos     Open Access   (SJR: 0.204, CiteScore: 0)
Estudos Históricos     Open Access   (Followers: 1)
EURE (Santiago) - Revista Latinoamericana de Estudios Urbano Regionales     Open Access   (SJR: 0.38, CiteScore: 1)
Ex aequo     Open Access  
FEM : Revista de la Fundación Educación Médica     Open Access  
Fides et Ratio : Revista de Difusión Cultural y Científica     Open Access   (Followers: 2)
Fisioterapia e Pesquisa     Open Access  
Fisioterapia em Movimento     Open Access  
Fitosanidad     Open Access  
Floresta e Ambiente     Open Access   (Followers: 1, SJR: 0.3, CiteScore: 0)
Folios     Open Access  
Food Science and Technology (Campinas)     Open Access   (Followers: 1, SJR: 0.467, CiteScore: 1)
Formación Universitaria     Open Access   (Followers: 4, SJR: 0.213, CiteScore: 1)
Frónesis     Open Access   (Followers: 2)
Frontera Norte     Open Access  
Gaceta Médica Boliviana     Open Access  
Gaceta Médica Espirituana     Open Access  
Galáxia (São Paulo)     Open Access  
Gayana (Concepcion)     Open Access   (SJR: 0.236, CiteScore: 0)
Gayana. Botanica     Open Access   (SJR: 0.234, CiteScore: 0)
Genetics and Molecular Biology     Open Access   (Followers: 15, SJR: 0.638, CiteScore: 2)
Geofísica internacional     Open Access   (SJR: 0.312, CiteScore: 1)
Gerokomos     Open Access   (Followers: 1, SJR: 0.257, CiteScore: 0)
Gestão & Produção     Open Access   (SJR: 0.156, CiteScore: 0)
Gestión y Política Pública     Open Access   (Followers: 2, SJR: 0.106, CiteScore: 0)
Hacia la Promoción de la Salud     Open Access  
Hallazgos     Open Access   (Followers: 1)
Hidrobiológica     Open Access   (SJR: 0.166, CiteScore: 0)
Historia     Open Access   (Followers: 2)
Historia (Santiago)     Open Access   (Followers: 1, SJR: 0.162, CiteScore: 0)
História (São Paulo)     Open Access   (SJR: 0.11, CiteScore: 0)
História, Ciências, Saúde - Manguinhos     Open Access   (Followers: 2, SJR: 0.144, CiteScore: 0)
Hoehnea     Open Access  
Horizonte Sanitario     Open Access   (Followers: 2)
Horizontes Antropológicos     Open Access   (Followers: 3, SJR: 0.233, CiteScore: 0)
Horticultura Brasileira     Open Access   (SJR: 0.605, CiteScore: 1)
HTS Theological Studies     Open Access   (Followers: 8, SJR: 0.448, CiteScore: 0)
Humanidades Médicas     Open Access  
IDESIA : Revista de Agricultura en Zonas Áridas     Open Access   (SJR: 0.223, CiteScore: 0)
Iheringia. Série Zoologia     Open Access   (Followers: 1, SJR: 0.26, CiteScore: 1)
Íkala : Revista de Lenguaje y Cultura     Open Access   (SJR: 0.112, CiteScore: 0)
Image & Text     Open Access   (Followers: 2)
Index de Enfermeria     Open Access   (Followers: 5, SJR: 0.113, CiteScore: 0)
Indo-Pacific J. of Phenomenology     Open Access   (Followers: 1)
Infectio     Open Access   (SJR: 0.133, CiteScore: 0)
Información Tecnológica     Open Access   (SJR: 0.197, CiteScore: 0)
Ingeniare : Revista Chilena de Ingenieria     Open Access   (Followers: 1, SJR: 0.239, CiteScore: 0)
Ingeniería Electrónica, Automática y Comunicaciones     Open Access  
Ingeniería Hidráulica y Ambiental     Open Access  
Ingeniería Industrial     Open Access  
Ingeniería Mecánica     Open Access   (Followers: 4)
Ingenieria Mecánica. Tecnologia y Desarrollo     Open Access   (Followers: 3)
Ingeniería y Competitividad     Open Access  
Ingenieria y Universidad     Open Access   (Followers: 1, SJR: 0.161, CiteScore: 1)
Ingeniería, Investigación y Tecnología     Open Access   (Followers: 1)
Innovar     Open Access   (SJR: 0.118, CiteScore: 0)
Interações (Campo Grande)     Open Access  
Interface - Comunicação, Saúde, Educação     Open Access   (Followers: 1, SJR: 0.417, CiteScore: 0)
Intersticios Sociales     Open Access   (Followers: 2)
Intervención     Open Access   (Followers: 2)
Intervención Psicosocial     Open Access   (SJR: 0.381, CiteScore: 1)
Intl. Brazilian J. of Urology     Open Access   (Followers: 4, SJR: 0.367, CiteScore: 1)
Intl. J. of Morphology     Open Access  
Intl. J. of Odontostomatology     Open Access   (Followers: 1)
Intl. Law: Revista Colombiana de Derecho Internacional     Open Access   (Followers: 3)
Investigación Administrativa     Open Access   (Followers: 2)
Investigación Bibliotecológica     Open Access   (Followers: 6, SJR: 0.274, CiteScore: 0)
Investigación Económica     Open Access   (Followers: 4, SJR: 0.132, CiteScore: 0)
Investigación y Desarrollo     Open Access   (Followers: 1)
Investigación y Educación en Enfermería     Open Access   (Followers: 1, SJR: 0.198, CiteScore: 0)
Investigaciones Geográficas     Open Access   (SJR: 0.246, CiteScore: 0)
Investigaciones Marinas     Open Access  
Iteckne     Open Access  
Iuris Tantum Revista Boliviana de Derecho     Open Access  
Ius et Praxis     Open Access   (SJR: 0.283, CiteScore: 0)
Izquierdas     Open Access   (SJR: 0.188, CiteScore: 0)
Iztapalapa : Revista de ciencias sociales y humanidades     Open Access   (Followers: 2)
J. of Applied Oral Science     Open Access   (SJR: 0.645, CiteScore: 2)
J. of Applied Research and Technology     Open Access   (SJR: 0.255, CiteScore: 1)
J. of Coloproctology     Open Access   (SJR: 0.167, CiteScore: 0)
J. of Energy in Southern Africa     Open Access   (Followers: 3, SJR: 0.249, CiteScore: 1)
J. of Epilepsy and Clinical Neurophysiology     Open Access   (Followers: 7)
J. of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 11, SJR: 0.146, CiteScore: 1)
J. of Seed Science     Open Access   (Followers: 1)
J. of Soil Science and Plant Nutrition     Open Access   (Followers: 11, SJR: 0.823, CiteScore: 2)
J. of Technology Management & Innovation     Open Access   (Followers: 5, SJR: 0.271, CiteScore: 1)
J. of the Brazilian Chemical Society     Open Access   (Followers: 2, SJR: 0.357, CiteScore: 1)
J. of the Brazilian Society of Mechanical Sciences     Open Access   (Followers: 2)
J. of the Chilean Chemical Society     Open Access   (Followers: 2, SJR: 0.201, CiteScore: 1)
J. of the Mexican Chemical Society     Open Access   (Followers: 2, SJR: 0.214, CiteScore: 1)
J. of the Selva Andina Research Society     Open Access   (Followers: 3)
J. of the South African Institution of Civil Engineering     Open Access   (Followers: 2, SJR: 0.174, CiteScore: 0)
J. of the Southern African Institute of Mining and Metallurgy     Open Access   (Followers: 6)
J. of Venomous Animals and Toxins     Open Access   (Followers: 2)
JISTEM : J. of Information Systems and Technology Management     Open Access   (Followers: 7)
Jornal Brasileiro de Nefrologia     Open Access   (SJR: 0.334, CiteScore: 1)
Jornal Brasileiro de Patologia e Medicina Laboratorial     Open Access   (SJR: 0.143, CiteScore: 0)
Jornal Brasileiro de Pneumologia     Open Access   (SJR: 0.448, CiteScore: 1)
Jornal Brasileiro de Psiquiatria     Open Access   (Followers: 2, SJR: 0.224, CiteScore: 0)
Jornal da Sociedade Brasileira de Fonoaudiologia     Open Access  
Jornal de Pneumologia     Open Access  
Jornal Vascular Brasileiro     Open Access   (SJR: 0.136, CiteScore: 0)
Justicia Juris     Open Access  
Kriterion: Revista de Filosofia     Open Access   (Followers: 1, SJR: 0.114, CiteScore: 0)
Kronos : Southern African Histories     Open Access   (Followers: 6)
La ventana. Revista de estudios de género     Open Access  
La zaranda de ideas     Open Access   (Followers: 1)
Laboreal     Open Access  
Lankesteriana     Open Access   (SJR: 0.458, CiteScore: 1)
Latin American Applied Research     Open Access   (Followers: 1)
Latin American J. of Aquatic Research     Open Access   (SJR: 0.289, CiteScore: 1)
Latin American J. of Economics     Open Access   (Followers: 1, SJR: 0.127, CiteScore: 0)
Latin American J. of Solids and Structures     Open Access   (Followers: 4, SJR: 0.522, CiteScore: 1)
Latinoamérica. Revista de estudios Latinoamericanos     Open Access   (Followers: 2)
Lecturas de Economía     Open Access  
Letras Históricas     Open Access   (Followers: 2)
Límite : Revista Interdisciplinaria de Filosofía y Psicología     Open Access  
Linguagem em (Dis)curso     Open Access  
Lingüística     Open Access   (SJR: 0.13, CiteScore: 0)
Lingüística y Literatura     Open Access   (Followers: 1)
Literatura y Lingüística     Open Access   (Followers: 1, SJR: 0.13, CiteScore: 0)
Lua Nova : Revista de Cultura e Política     Open Access   (SJR: 0.274, CiteScore: 0)
Luna Azul     Open Access  
Machado de Assis em Linha     Open Access   (SJR: 0.101, CiteScore: 0)
Madera y Bosques     Open Access   (Followers: 2)
Maderas. Ciencia y tecnología     Open Access   (Followers: 2, SJR: 0.546, CiteScore: 1)
Magallania     Open Access   (SJR: 0.354, CiteScore: 0)
Mana - Estudos de Antropologia Social     Open Access   (Followers: 2, SJR: 0.355, CiteScore: 0)
Manuscrito     Open Access  

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Similar Journals
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Polímeros : Ciência e Tecnologia
Journal Prestige (SJR): 0.244
Citation Impact (citeScore): 1
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0104-1428 - ISSN (Online) 1678-5169
Published by SciELO Homepage  [893 journals]
  • Extraction and analysis of the parietal polysaccharides of acorn pericarps
           from Quercus trees

    • Abstract: Abstract Acorns produced by Quercus trees are currently underexploited and undervalued. To evaluate the commercial and health benefits of acorns, we examined the cell wall components of acorn pericarps from Quercus suber and Quercus ilex, growing in North-Western Algeria. Acorn pericarps were sequentially extracted and the polysaccharide fractions were analyzed by gas liquid chromatography and Fourier-transform infrared spectroscopy. The lignocellulosic fraction was the major component of Q. suber and Q. ilex cell walls (37.19% and 48.95%, respectively). Lower amounts of pectins and hemicelluloses were also found in both species. Hemicellulose extracts from the two species contained xylose as the major monosaccharide (ranging from 36.7% to 49.4%). Galacturonic acid was the major component of hot water- or ammonium oxalate-extracted pectins from both species (ranging from 20.6% to 46.8%). The results reported in this paper reveal that acorn pericarp cell walls from these two oak could be potential sources of bioactive compounds.
       
  • Bionanocomposites of PLA/PBAT/organophilic clay: preparation and
           characterization

    • Abstract: Abstract The objective of this study was to develop bionanocomposites from blends of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) and from 3% and 6% bentonite clay. Initially, the bentonite clay was treated with Praepagen salt, and the properties of the modified clay were evaluated. After the organophilization of the clay was completed, 50:50 blends of PLA/PBAT were prepared, and 3 and 6% clay was added. To test the dispersion of the system, the blending sequence was performed using eight different sequences for the addition of clay to the PLA/PBAT matrices. The mixtures were prepared in a twin screw extruder, and the specimens were subsequently injection molded. The investigated mechanical and morphological properties included the yield strength, yield strain, tensile and bending elastic modulus, and scanning and transmission electron microscopy analyses. The results of this study showed increases of the mechanical properties when nanoparticles were added and the formation of bionanocomposites with intercalated structures.
       
  • Influence of ZnO on the properties of elastomeric compositions and their
           leached extract

    • Abstract: Abstract The reductionin zinc oxide (ZnO) content in elastomeric compositions has become a subject due to the deleterious effect of zinc ions on aquatic organisms. The purpose of this study was to develop elastomeric compositions containing 0, 1, 3 and 5 phr of ZnO aiming at assessing the influence of the different contents on the rheometric, mechanical and thermal properties. The release of the zinc (Zn) content by leaching, at each step of the production and after the ageing was also assessed. All ZnO-containing compounds had similar rheometric, thermal and mechanical properties. Also, during and after exposure to accelerated ageing the released contents were similar for all compositions regarding the residual ZnO percent. In conclusion, the utilization of the 3 phr ZnO content is viable for the replacement of the usual amount employed.
       
  • Influence of water absorption on glass fibre reinforced IPN composite
           pipes

    • Abstract: Abstract Glass fibre reinforced composite pipes were fabricated by using an IPN blend of 0%, 10%, 20%, 30%, 40%, 50% PU prepolymer (Polyurethane) with VER(Vinylester) resin. The prepared IPN (Interpenetrating polymer networks) composite pipes were subjected to boiling water immersion tests in order to study the effect of moisture absorption characteristics. The Burst strength and Hoop strength of water immersed specimens were evaluated (3, 6, 9, 12 months) and compared along with dry composite specimens. It was found that, percentage of moisture uptake was significantly reduced with increase in PU loading into the IPN system as well the Burst strength and Hoop strength of the specimens were found to be diminishing with raise in percentage of moisture uptake and raise in temperature; contrarily, the addition of PU significantly reduced the moisture intake, in addition to that the PU added IPN pipe offers better mechanical strength while compared with neat Vinylester pipes.
       
  • Influences of the mesh in the CAE simulation for plastic injection molding

    • Abstract: Abstract Although computer-aided engineering (CAE) software has been used for many years in the plastic industry, identifying the most appropriate mesh geometry and density remains a challenge. It can affect the accuracy of the simulation, the time and the costs. The evaluation of the most suitable mesh is not easy because the difficulties to obtain the real the values of the pressure and temperature inside the mold. The current work investigates this issue. A mold was manufactured and sensors were installed in its interior. CAE simulations using different mesh geometries and densities were evaluated against the experimental data. The results showed that the computational time was mostly influenced by the mesh geometry. The use of 2D mesh and lower density can lead to a faster and more precise simulation of pressure inside the mold and 3D mesh with lower density can provide a faster and precise simulation of the temperature.
       
  • In vitro evaluation of PVA gels loaded with Copaiba Oil and
           Duotrill®

    • Abstract: Abstract Enrofloxacin can be slowly delivered through polymeric systems and the addition of oil could increase the polymeric gels hydrophobicity and help the continuous release. The present work intended to develop and characterize microstructurally (XRD and FTIR) and in vitro (swelling and antimicrobial tests) the PVA hydrogels loaded with copaiba oil and Duotrill (enrofloxacin) to treat bacterial infections, as pyelonephritis, in the veterinary field. Duotrill® and oil combined diminished the gels degree of crystallinity and it was observed interaction between phases due to a new band found only in PVA hydrogels loaded with copaiba oil and Duotrill (PVA-D-O) FTIR spectrum. The samples with oil swelled less than samples without it, where copaiba oil altered the samples’ hydrophilicity. PVA-D-O presented lower weight loss and higher gel fraction than PVA, indicating the loaded material increased the gels stability. All samples containing oil and Duotrill® inhibited S. aureus.
       
  • Synthesis and characterization of microalgae fatty acids or Aloe
           vera
    oil microcapsules

    • Abstract: Abstract It’s proposed a single methodology for the encapsulation of Aloe vera oil or microalgae fatty acids using the complex coacervation process between gelatin and gum arabic. Although a very recurrent method, it is not trivial to establish a single coacervation methodology to encapsulate different compounds. The optimal synthesis conditions, that resulted in the best yield and encapsulation efficiency, are 1:1 (m/m) wall-to-core ratio, a temperature of 40°C and agitation speed of 10,000 rpm. Optical microscopy analysis revealed that the microcapsules are spherical, have average diameters of 112 μm (A. vera) and 118 μm (microalgae) and do not form agglomerates. The microcapsules were characterized by the osmotic pressure at which they ruptured, allowing the calculation of their mechanical resistance, which resulted in 392 MPa (A. vera) and 425 MPa (microalgae). The presented optimized methodology to encapsulate both compounds aims to contribute to their efficient and rational use, especially in cosmeceutical applications.
       
  • Effects of miniemulsion operation conditions on the immobilization of BSA
           onto PMMA nanoparticles

    • Abstract: Abstract Polymer nanoparticles have been widely used in many biomedical applications, constituting a major incentive for immobilization of proteins. Poly(methyl methacrylate) nanoparticles were synthesized through miniemulsion polymerizations and used as supports for bovine serum albumin immobilization. Particularly, the effects of surfactant type (anionic sodium dodecyl sulfate and cationic cetyl trimethyl ammonium bromide) surfactant concentration and monomer holdup on some of the final nanoparticle properties (particle sizes, zeta potential and protein load) were characterized with help of statistical experimental designs for the first time. Results showed that the characteristics of the surfactant controlled the BSA adsorption efficiency, with enhanced rates of adsorption on the anionic particle surfaces, showing that the surfactant exerts fundamental effect on functionalization of emulsified polymer particles, which must be explicitly acknowledged in studies of polymer particle functionalization with proteins. Finally, BSA adsorption was shown to follow a multilayer process, given the better fitting with the Freundlich model.
       
  • Controlled release fertilizer encapsulated by a κ-carrageenan
           hydrogel

    • Abstract: Abstract The release kinetics of nitrogen and phosphorous of a granulated fertilizer, encapsulated in a κ-carrageenan-based hydrogel (CBH), was evaluated in order to determine its release mechanism given the potential this hydrogel has as coating material for controlled release fertilizers (CFRs). The effect of pH on the release properties was also investigated. The relationship between the NH4+, NO3-, and PO43- release of encapsulated fertilizers and time was determined by short- and long-term laboratory incubations. The mechanism of the release of nutrient ions was determined by comparing the release data with the zero-order, first-order, Higuchi, Hixon-Crowell and Korsmeyer-Peppas kinetic models. The findings showed that the Korsmeyer-Peppas model could be used to describe the release characteristics of the nutrients in the encapsulated fertilizers and that non-Fickian diffusion is the main release mechanism. The experimental hydrogel showed a high water retention capacity able to absorb 300 times its weight water.
       
  • Plastics floatability: effect of saponin and sodium lignosulfonate as
           wetting agents

    • Abstract: Abstract Froth flotation is the most common process in mineral processing. For the separation of plastic mixtures by flotation, the use of appropriate wetting agents is mandatory. The floatability of six post-consumer plastics was studied at different concentrations of the wetting agents, saponin and sodium lignosulfonate. Also, the influence of size and shape of the particles were analyzed. Contact angle and floatability of the six plastics decreased with increasing wetting agents concentration. The order of floatability is similar to the order of the contact angles values. However, the influence of the wetting agents in the plastics floatability is more pronounced than in the contact angle. Floatability decreased with the increase of particle density, particle size and spherical shape. For fine particles floatability is fundamentally conditioned by the contact angle, while for coarse particles floatability is fundamentally conditioned by the particles weight.
       
  • Silver nanoparticles incorporated PVC films: evaluation of structural,
           thermal, dielectric and catalytic properties

    • Abstract: Abstract In this work, silver nanoparticle – polyvinylchloride (SNC-PVC) composites were synthesized by loading 2.5% to 10.0% silver ions to PVC using simple solution casting technique. Material properties including dielectric, thermal stability were discussed in some detail. Incorporation of silver nanoparticles (SNPs) in the PVC matrix was confirmed by UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) and Field Emission Scanning Electron Microscopy (FE-SEM). FE-SEM confirms the shape of the SNPs are roughly spherical with average size of the SNPs in the range of 60 - 80 nm. The thermal degradation studies were analysed via sensitive graphical Broido’s method using Thermogravimetric analysis (TGA). The resulting SNC-PVC films, especially with 10% silver loading showed improved catalytic performance during the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of aqueous sodium borohydride with apparent rate constant 1.956 × 10-3 sec-1 at ambient temperature.
       
  • Crosslinking starch/oat hull mixtures for use in composites with PLA

    • Abstract: Abstract Modification of composite components has been proposed as a tool to improve their functional properties. The present work studied crosslinking of a starch/oat hull mixture by reactive extrusion with sodium trimetaphosphate (STMP), for application in composites with polylactic acid (PLA). The treated mixture was characterized regarding degree of substitution, FT-IR, and thermal properties. The native and modified mixtures were processed by injection molding, together with PLA and glycerol. The microstructure, mechanical properties, shrinkage, density, and thermal properties of the composites were determined. The FT-IR results, increase in phosphorus content and thermal stability after starch/fiber mixture treatment with STMP suggested the occurrence of crosslinking. Better interfacial adhesion between oat hulls and the polymeric matrix was observed in electron micrographs of the composites containing the modified components. Slight decreases in tensile strength and modulus were observed in the modified composites, suggesting that extrusion and subsequent milling may have broken some structures/linkages.
       
  • Grafting polypropylene over hollow glass microspheres by reactive
           extrusion

    • Abstract: Abstract Hollow glass microspheres HGM are light, round, hollow, hydrophilic microspheres used to produce polyolefin composites with reduced density. To maintain mechanical strength, it is necessary to improve the adhesion between the polymer matrix and the microspheres, which is done by a compatibilizer. For polypropylene composites a maleic anhydride grafted polypropylene copolymer PP-g-MAH is employed. The melt mixing is done in a reactive extrusion when the maleic group of the compatibilizer reacts with hydroxyl groups present at the microspheres’ surface, grafting a long PP chain. The aim of this work is to quantify the esterification grafting conversion and its efficiency during the reactive extrusion to the formation of PP/HGM composites compatibilized with PP-g-MAH. Techniques like TGA, FTIR and SEM were used to quantify the grafted PP content formed and the efficiency of the esterification reaction, which is mainly dependent of the compatibilizer concentration and reactive extrusion temperature.
       
  • System to measure torsion modulus of polymers using the deformation energy
           method

    • Abstract: Abstract This paper presents an alternative method to measure the torsion modulus, G, for samples of polymers. We constructed a measurement system with a force sensor (FS) and a rotational movement sensor (RMS) to obtain a relationship between force (F) and torsion angle (θ). An expression that could return the value of G was deduced using the deformation energy method. This technique is nondestructive and independent of knowing the value of Poisson’s ratio. Samples with different diameters of polytetrafluoroethylene (PTFE) were submitted to quasi-static torsion at the same aspect ratio. The aim was to present and validate the use of the technique for a known polymer. The approximate value of 350 MPa of the torsion modulus G was found for PTFE samples. As the values obtained are within the limits found in the literature, the technique can be used to study samples of polymers and other materials.
       
  • Effect of moringa and bagasse ash filler particles on basalt/epoxy
           composites

    • Abstract: Abstract This study evaluated the effect of moringa and nano ash filler particles on mechanical, chemical corrosion and moisture absorption of basalt fiber/epoxy composites. Epoxy resin and Araldite HY951 hardener was used as matrix along with the inclusion of filler particles while the bi-directional woven basalt fiber mat was used as the reinforcement in fabricating composites using hand layup technique. Three different composites i.e. Plain BF + matrix with no filler particles, BF + matrix with 10 wt, % moringa ash and BF + matrix with 10 wt, % bagasse ash were fabricated and tested according to the ASTM standards to determine the mechanical properties and chemical corrosion resistance. According to the experimental test results, the composites with moringa ash inclusion showed better properties than the bagasse ash inclusion and with no filler added composites.
       
 
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