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.

ABSTRACT: The toughening of polyamide 6 is desirable for many applications and may be obtained by adding a phase to the elastomeric matrix. However, this leads to a loss in its rigidity characteristics. Therefore, this study aimed at developing blends of polyamide 6/compound by recycled rubber (SBR-R), with the addition of compatibilizer graphitized polyethylene and polypropylene with maleic anhydride method by mixing in the molten state in order to obtain a balance between stiffness and toughness. The systems were prepared in several compositions, and their rheological properties and spectroscopy in the Fourier transform infrared were studied by means of rheological curves obtained in an internal mixer of Haake Buchler. The results obtained with the rheological study and Fourier transform infrared showed that mixtures of polyamide 6/graphitized polyethylene with maleic anhydride presented the best results compared to those of polyamide 6/ graphitized polypropylene with maleic anhydride, probably indicating reaction between the components. Thus, it was chosen graphitized polypropylene with maleic anhydride as a compatibilizing agent for carrying out other characterizations. Blends of polyamide 6/compound by recycled rubber/ graphitized polypropylene with maleic anhydride and their properties were analyzed by means of mechanical tests (tensile and impact), dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. The impact strength and elastic modulus of the blends compatibilized reduced somewhat when compared to polyamide 6. Therefore, these results indicate a good prospect of application of industrial waste, minimizing the negative effect on the environment and adding value to a disposable material.