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The addition of natural fiber is a biodegradable polymer matrix has been an alternative for composites having enhanced thermal and mechanical properties. Considering that the properties of the composite can be influ-enced by the processing conditions, type and concentration of the dispersed phase, this study aimed to obtain composites from a commercial blend made of Poly (butylene adipate co-terephthalate) - PBAT / Starch (EB), of biodegradable character, and rice husk (CA). Initially composites were prepared PBAT / starch containing 10, 20 and 30% (CA) using a dual extruder and internal mixer screw. Subsequently, there were certain me-chanical and thermal properties of the systems obtained. The results of mechanical properties showed that the elastic modulus of the composite was affected by the type of employee processing the composites obtained in the extruder have a higher modulus than the composite obtained in the mixer: 92% higher in composites with 10% load and 38% higher in composites with 30% filler. The impact resistance decreased significantly and the tensile strength increased moderately with rice husk content, regardless of the type of processing used. The impact resistance of composites with 30% load is approximately 33% the impact resistance of the pure blend. In the tensile strength, there was a 25% increase in the composite with 30% filler. SEM analyzes indi-cated that the filler particles were adequately wetted by the matrix and the adhesion load / matrix was good. The evaluation of the results obtained with the DSC analysis indicated that the addition of CA in the extruded composite alter the crystallization temperature ranging from 75 °C pure sample to 101°C for samples with rice husk, as a result attributable to the nucleating effect caused by the greater this type of load dispersion processing. © 2016, Universidade Federal do Rio de Janeiro. All rights reserved. Source

Simoes A.N.,Unidade Academica de Engineering de Materiais | Neiva L.S.,Unidade Academica de Engineering de Materiais | Simoes V.N.,Unidade Academica de Engineering de Materiais | Rodrigues M.G.,Federal University of Campina Grande | Gama L.,Unidade Academica de Engineering de Materiais

In recent years, heating and driving chemical reactions by microwave energy has been an increasingly popular topic in the scientific community, and so in the field of zeolite. Thus, this paper aims to study the effect of temperature on the achievement of zeolite Y synthesized by microwave. The synthesis temperature was varied from 100 °C to 90 °C. The samples were characterized by X-ray diffraction, scanning electron microscopy and nitrogen adsorption. The results show the strong influence of temperature on all the final characteristics of the samples. As the Y zeolite obtained at 90 °C by microwave, but 100 °C was optimal temperature for obtaining the zeolite with good crystallinity. Source

Luna C.B.B.,Unidade Academica de Engineering de Materiais | Silva D.F.,Federal University of Sao Carlos | Araujo E.M.,Unidade Academica de Engineering de Materiais | Melo T.J.A.,Unidade Academica de Engineering de Materiais | Oliveira A.D.,Unidade Academica de Engineering de Materiais
Revista Materia

The combination of polymer is an alternative to obtain materials with properties that, in general, are not found in a single material. The goal of this work was to produce polymer blend with polystyrene (PS) as a matrix and recycled rubber compound (SBR) as a minor phase, in order to obtain superior properties to PS. The combination of polystyrene/ composed recycled rubber was prepared in a double screw corrotational extruder and, subsequently, the extruded pellets were molded by injection. These were characterized by mechanical tests, dynamic mechanical thermal analysis (DMTA), heat deflection temperature (HDT) and scanning electron microscopy (SEM). It was observed that there was no significant loss in HDT and on tensile strength. The DMTA tests showed the presence of two peaks transition, a reference to the PS Tg and another regarding the Tg of PB. The morphology showed a reduction in the quantity of voids and in the size of the particles when the mixture was compatibilized with 5% SBS. The PS/SBR blends are an alternative to the reuse of footwear wastes, as well as to add value to a material that would be discarded. © 2015, Universidade Federal do Rio de Janeiro. All right resurved. Source

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