Abstract Using natural fibers in composites presents a wide range of applications, from furniture to airplanes. In polymeric composite, the use of fiber is to boost strength and stiffness. However, this material presents low mechanical properties compared to virgin polymers due to hydrophilic nature of the fiber and hydrophobic nature of the polymer. It can result in weak bonding matrix/fiber which may cause incompatibility problem in bonding fibers with most of the polymer matrices. To achieve compatibility between surfaces there is a need to modify them, and one alternative is using coupling agents. Maleated coupling agents stand out as option, but their source is petroleum-derived polyolefin. Researchers have been seeking for more environmentally friendly alternatives to replace these materials. Therefore, this work aims to bring a comprehensive review of the mechanical behavior of maleated and ecological coupling agents. Based on the literature, resistance, flexural, and tensile strength were properties discussed. applications airplanes composite stiffness However matrixfiber matrix matrices them option petroleumderived petroleum derived polyolefin materials Therefore literature resistance flexural discussed

Abstract This work aimed to obtain and analyze composite materials made from green polyethylene and calcium carbonate extracted from chicken eggshells. The shells were collected and prepared for later extraction of calcium carbonate. With the X-ray diffraction analysis it was possible to confirm that both the in natura reinforcement and the calcined one, have the same polymorph mineral (calcite). With regard to thermal behavior, compounds with in natura reinforcement showed greater mass loss due to the moisture contained in them. The results showed a significant increase in Young’s moduli of the composites compared to the pure polymer. The scanning electron microscopy showed good dispersion and adhesion between the reinforcement materials and matrix. In view of the results, eggshells have the potential to be used as fillers, where greater rigidity is required. Since these materials come from a waste material, with low cost, their use becomes even more viable.

This work developed ternary films based on Poly(Lactic Acid) (PLA), Cloisite 30B (C30B) and Oregano Essential Oil (OEO) as proposal to be applied in food packaging. The films thus manufactured were unscathed, with reduced surface defects. Their thickness and moisture content varied according to the composition and content of each component in the formulation. Optical micrographs indicated a homogeneous morphology, with good distribution of clay in the matrix. FTIR data confirms the incorporation of OEO into the films. TGA analysis indicated that the thermal stability of the films was not significantly affected by the incorporation of C30B and OEO. OEO incorporation did not promote an efficient antimicrobial action which is probably due to its retention by the clay. Further studies are needed to confirm this hypothesis. The combination between C30B and OEO in the PLA polymeric matrix is a promising proposal.

Abstract Blends of Polystyrene (PS) and Poly(ε-caprolactone) (PCL) were twin screw extruded, two PSs, with low and high melt flow rate (MFR) were used and their feasibility within PCL investigated by means of torque rheometry, mechanical tests, heat deflection temperature (HDT) and scanning electron microscopy (SEM); predictive models were utilized to evaluate interfacial adhesion in PS/PCL blends. Results show that no decreasing was verified in torque rheometry plots suggesting thermally stable blends; elastic modulus decreased and elongation at break increased in PS/PCL blends compared to neat PS. PS/PCL blends with low MFR PS and higher PCL amount are more thermodynamically stable. Higher HDT was verified in PS/PCL blends. The trends observed applying predictive models are indicative of poor adhesion between PCL and PS, agreeing with coalescence and phase segregation as verified in SEM images. PS/PCL systems with higher MFR PS presented the best results.

Abstract High-density polyethylene (HDPE) reinforced with cellulose from rice husk (RH) were prepared and studied. The RH biomass was submitted to acid extraction and bleaching process and then analyzed for its cellulose extraction efficiency by X-ray diffraction (XRD) and Fourier transformation infrared spectroscopy (FTIR). After that, the RH cellulose (RHC) was incorpored to the HDPE matrix by melt blending with different filler contents (5, 10 and 15 wt%), and then characterized in terms of mechanical properties and morphology. The RHC incorporation in the HDPE matrix resulted in an increase in elastic modulus regardless the filler content added; also, the impact resistance was maintained for RHC contents up to 10%. The morphological analysis of the composites showed that the cellulose was well dispersed in the matrix, which contributed to the improvement of the final rigidity of these materials, indicating the feasibility of incorporating this residue in the production of HDPE composites.

RESUMO O presente trabalho teve como objetivo empregar resíduos agroindustriais, especificamente fibras celulósicas extraídas de talos de casca de banana, para a obtenção de acetato de celulose. Tal produto por sua vez, foi utilizado como matriz em um compósito antimicrobiano para uso em embalagens de alimentos, constituído de acetato de celulose e partículas de prata. As referidas partículas foram produzidas por meio de síntese hidrotérmica assistida por micro-ondas a partir da redução do nitrato de prata, utilizando o citrato trisódico. As partículas de prata apresentaram um diâmetro médio de 433,6 nm. O compósito obtido foi caracterizado por microscopia eletrônica de varredura (MEV), testes de resistência à tração, análise termogravimétrica e espectroscopia no infravermelho por transformada de Fourrier (FTIR) e no UV-visível. Os resultados mostraram uma tensão de ruptura de aproximadamente 43 MPa, 25% maior que a apresentada por polímeros comerciais sem a adição de cargas. Além disto, obteve-se propriedades bactericidas com relação as bactérias Staphylococcus aureus e Escherichia coli, quando em contato direto com o filme formado pelo compósito.

ABSTRACT The present work had the objective to use agroindustrial residues, specifically cellulosic fibers from banana peel stalks, to obtain cellulose acetate. This product, in turn, was used as a matrix in an antimicrobial composite for food packaging, consisting of cellulose acetate and silver particles. The silver particles were produced by microwave-assisted hydrothermal synthesis from the reduction of silver nitrate using trisodium cit-rate. The obtained particles had a mean diameter of 433.6 nm. The composite was characterized by scanning electron microscopy (SEM), tensile strength test, thermogravimetric analysis, Fourier trans-form infrared (FTIR) spectroscopy and UV-visible spectroscopy. The results showed a fracture strain 25% greater than the commercial polymers without the addition of fillers, achieving about 43 MPa. In addition, bactericidal properties were obtained in relation to the bacteria Staphylococcus aureus and Escherichia coli when in direct contact with the composite film formed.

The effect of maleic anhydride (MA) content on morphological, thermal, thermomechanical and mechanical properties of PA6/AES/MMA-MA (66.5/28.5/5 wt%) system was investigated. In general, the simple incorporation of MMA-MA to PA6/AES system is responsible for enhancements in mechanical performance. PA6/AES/MMA-MA3% and PA6/AES/MMA5% exhibited similar morphology and final properties, indicating no MA content effect on the studied system. On the other hand, PA6/AES/MMA-MA10% exhibited a quite different morphology and lower mechanical performance compared to the other compatibilized blends. Such unexpected behavior was not attributed to the effective maleic anhydride content in this composition, but to the reduced molar mass resulted from the excess of non-reacted MA monomer during the synthesis procedure.

Abstract The reuse of rubber waste is very important today, both to reduce the harmful effects on the environment, and to reduce the cost of new material development. Considering that most of the studies reported in literature refer to the reuse of tire waste, this article aims to evaluate the influence of styrene-butadiene-styrene (SBS) and styrene-(ethylene-butylene)-styrene grafted with maleic anhydride (SEBS-MA) compatibilizers on the blend performance of polystyrene (PS)/styrene-butadiene rubber residue (SBRr), which come from the footwear industry. The blends were prepared in a co-rotating twin screw extruder and then were molded by injection. They were analyzed by impact and tensile tests, heat deflection temperature (HDT), ductile-brittle transition temperature, dynamic mechanical thermal analysis (DMTA) and transmission electron microscopy (TEM). The results evidenced that the use of any of the compatibilizers on the PS/SBRr blend significantly increased the impact strength, while the tensile properties and HDT were lower when compared to the polymer matrix. The ductile-brittle transition temperature remains at approximately 25°C range for all the blends. In general, it has been proved that the SBS was the most effective compatibilization process in the PS/SBRr system. The DMTA test shows the presence of two distinct temperature peaks. The morphologies obtained by TEM of binary and ternary blends were quite different and typical of immiscible blend. The results show a good perspective regarding the use of industrial waste (SBRr), since it may enhance a material that would be discarded.

RESUMO O reaproveitamento de resíduos de borracha é de extrema importância atualmente, tanto para minimizar os efeitos nocivos no meio ambiente, quanto para reduzir o custo no desenvolvimento de novos materiais. Considerando que a maioria dos trabalhos relatados na literatura se refere ao reaproveitamento dos resíduos de pneus, o presente trabalho tem como objetivo avaliar a influência dos compatibilizantes SBS e SEBS-MA no desempenho da mistura de PS/resíduo de borracha da indústria de calçado (SBR), utilizando 5% em peso destes compatibilizantes. As misturas inicialmente foram preparadas em uma extrusora de rosca dupla corrotacional e, posteriormente, os grânulos extrudados moldados por injeção. Estas foram analisadas por ensaios de impacto, flexão, temperatura de deflexão térmica (HDT), termogravimetria (TG) e microscopia eletrônica de varredura (MEV). Os resultados evidenciaram que a utilização de qualquer um dos compatibilizantes na mistura PS/SBR aumentou expressivamente a resistência ao impacto, enquanto que as propriedades de flexão e HDT foram inferiores em relação à matriz polimérica. Em geral, ficou comprovado que o SBS é mais eficaz no processo de compatibilização do sistema PS/SBR, aumentando em 320% a resistência ao impacto em relação ao PS, bem como tendo uma perda de apenas 10,9% da HDT. Os resultados de termogravimetria ilustraram que a mistura PS/resíduo apresentou uma maior estabilidade térmica, em relação ao PS puro, para temperatura superior a 376ºC. As morfologias apresentadas pelas misturas ternária e binária foram bastante diferentes e típicas de misturas imiscíveis. Estes resultados mostram uma boa perspectiva de uso destes rejeitos industriais (SBR), uma vez que se pode valorizar um material que seria descartado. Além disso, tem a possibilidade de desenvolver um novo material com boas propriedades, bem como minimizar o efeito negativo desses rejeitos nos ecossistemas.

ABSTRACT The reuse of rubber residue is extremely important nowadays, both to minimize the bad effects to the environment and to reduce the costs of new materials development. Seeing that, most of the reported papers in literature refer to the reuse of tire rubber, this work aims to evaluate the influence of SBS and SEBS-MA compatibilizers on the performance of PS/rubber residue (SBR) mixture from shoes industry, using 5% wt. of these compatibilizers. The mixtures were initially prepared in a co-rotational twin screw extruder and the extruded pellets were later molded by injection. The samples were analyzed by impact, flexural, heat deflection temperature (HDT), thermogravimetry (TG) and scanning electron microscopy (SEM) experiments. The results evidenced that the use of any compatibilizers in the PS/SBR mixtures significantly increased the impact strength whereas the tensions and HDT properties were lower in relation to polymer matrix. It was proved that the SBS is more efficient in the compatibilizing process of PS/SBR system, increasing 320 % the impact strength compared to PS, as well as having a 10.9 % lost only in the HDT. The results of TG illustrated that the PS/residue mixture presented a higher thermal stability in relation to the pure PS, for temperature over 376ºC. The morphologies presented from ternary and binary mixtures were clearly different and typical of immiscible blends. The results showed a good perspective of this industries wastes (SBR) use, once it was possible to value a material that would be discharged. Besides, there is the possibility to develop a new material with good properties, as well as minimize the negative effect of these wastes in the environment.

Misturas de polímeros constituem alternativa para a obtenção de materiais com propriedades que, em geral, não são encontradas em um único material. O objetivo deste trabalho foi produzir misturas poliméricas a partir de uma matriz de poliestireno (PS) com composto de borracha reciclada (SBR) visando à obtenção de propriedades superiores ao PS. As misturas de poliestireno/composto de borracha reciclada foram preparadas em uma extrusora de rosca dupla corrotacional, com adição de agente compatibilizante e, posteriormente, os grânulos extrusados foram moldados por injeção. Estas foram caracterizadas por ensaio mecânico de tração, análise térmica-dinâmico-mecânica (DMTA), temperatura de deflexão térmica (HDT) e microscopia eletrônica de varredura (MEV). Observou-se que não houve perdas significativas da HDT e da resistência à tração. O ensaio de DMTA evidencia a presença de dois picos de transição distintos, um referente a Tg do PS e o outro referente a Tg do polibutadieno (PB). A morfologia ilustrou uma redução da quantidade de vazios e do tamanho das partículas quando a mistura foi compatibilizada com 5% de SBS. As misturas de PS/SBR são uma alternativa para o reaproveitamento dos resíduos de calçados, bem como, uma forma de agregar valor a um material que seria descartado.

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.

O efeito da organofilização da argila no comportamento mecânico, morfológico e termo-mecânico de nanocompósitos baseados em blendas de poliamida 6 )/acrilonitrila-EPDM-estireno foi estudado. Três nanoargilas foram utilizadas para a preparação dos nanocompósitos: duas montmorilonitas comerciais modificadas organicamente (Cloisite®30B and Cloisite® 20A) e uma montmorilonita sódica não modificada (Cloisite®Na+). Difração de raios-X em alto ângulo, microscopia eletrônica de transmissão e testes de tração e resistência ao impacto foram utilizados para avaliar o efeito da organofilização da nanoargila na morfologia e propriedades mecânicas dos materiais. As propriedades termo-mecânicas foram avaliadas por análise dinâmico mecânica e temperatura de deflexão térmica. Os resultados mostraram que a modificação da nanocarga afeta simultaneamente o grau de reforço da matriz, dispersão das lamelas de argila na blenda e tamanho da fase dispersa AES. A adição das diferentes nanoargilas aumenta o módulo elástico de todos os nanocompósitos ternários em relação à blenda pura sem argila. Por outro lado, um aumento na tenacidade foi obtido apenas para os sistemas com Cloisite®Na+. Um aumento significativo no módulo de armazenamento e HDT foi observado pela incorporação da Cloisite®30B na blenda.

The effect of clay organophilization on mechanical, morphological and thermo-mechanical behavior of polyamide-6/acrylonitrile-EPDM (ethylene/propylene/diene elastomer)-styrene blends was studied. Three nanoclays were used for the preparation of nanocomposites: two commercial organically modified montmorillonites (Cloisite®30B and Cloisite® 20A) and an unmodified sodium montmorillonite (Cloisite®Na+). We used wide angle X-ray scattering, transmission electron microscopy and mechanical tests to evaluate the effect of clay modification on the morphology and mechanical properties of the nanocomposites. The thermo-mechanical properties were characterized using dynamic mechanical analysis and heat distortion temperature (HDT). The results show that the modification of clay affected simultaneously the degree of PA6 matrix reinforcement, dispersion of the clay lamellas in the blend and size of the dispersed phase AES. The incorporation of different nanoclays increase the elastic modulus of all the ternary nanocomposites compared to the neat blend. An increase in the toughness is obtained only for systems with Cloisite®Na+. A significant increment in the storages modulus and HDT was observed by the incorporation of Cloisite®30B in the PA6/AES blends.