The preparation of a facilitated transport membrane of polyurethane (PU) containing silver nanoparticles is reported. The propylene and propane sorption was investigated aiming at the selective separation from C3s mixtures. The silver particles were photogenerated in situ into the polyurethane matrix using UV light radiation and silver triflate (AgCF3SO3) as precursor. The morphological properties of these membranes (PUAg) reveled great dispersion of silver particles, which size was smaller than 110 nm. The propylene solubility in PUAg resulted more than four times superior to the one for the pure PU membrane, revealing the high affinity between silver and propylene. Flory–Huggins theory was more accurate to describe the propylene sorption behavior in PUAg than Henry's model. The ideal solubility selectivity of PUAg membrane resulted 24.4, indicating that there is a good potential for an industrial application aiming at the separation of propylene/propane. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42916.

Around the world, concern is growing about the amount of waste rubber going into landfills. Policymakers are encouraging researchers to find innovative ways to recycle this waste. In this study, as part of an effort to recycle waste rubber (EPDMR) as filler in compositions of EPDM, we prepare a terpolymer of ethylenepropylene-diene with 1-dodecanethiol (EPDMSDD). We use it as a compatibilizing agent to improve adhesion and incorporation of the residue (EPDMR) in EPDM/EPDMR blends. We synthesize and characterize EPDMSDD through 13 C-NMR and FTIR spectroscopy. We evaluate the effect of the compatibilizer EPDMSDD using vulcanization parameters, such as optimum cure time, scorch time, and torque. To evaluate its effect on the interaction between EPDMSDD/EPDMR, we carried out mechanical tests of samples with and without EPDMSDD. Our findings show that the tensile strength and elongation increased with the addition of EPDMSDD, indicating a better interaction between EPDMR/EPDM. Tear strength also increased with the presence of EPDMSDD, particularly for the amount of 70 and 80 phr of EPDMR. This suggests a good adhesion between the phases in high amounts of waste. The micrographs of the mixtures revealed that the addition of EPDMSDD improved the dispersion of the EPDMR in the EPDM phase.

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In this work, acrylonitrile‐butadiene rubber / poly(methyl methacrylate) (XNBR/PMMA) blends were obtained through in situ polymerization of methyl methacrylate (MMA) monomer in XNBR rubber particles. Firstly, the XNBR rubber was swollen with MMA and then the polymerization was carried out in an aqueous medium, keeping the rubber particles in suspension. The results of the swelling tests indicated that mass transfer of MMA to rubber particles is more efficient in aqueous system. Fourier Transform Infrared (FTIR) analyses revealed the presence of PMMA in the XNBR phase. Thermo‐gravimetrical (TG) analyses indicated that as much as 10% of PMMA was present in the blends. Scanning electron microscopy (SEM) analyses revealed that PMMA was dispersed in the XNBR phase, indicating the efficiency of the MMA polymerization inside the XNBR rubber particles.

ácido graxo linolênico (EPDMAG). Os resultados de propriedades mecânicas mostraram que o EPDMSDD fornece a melhor combinação de resistência à tração e rasgamento associado à processabilidade. A adição dos agentes EPDMAE e EPDMAG melhorou a processabilidade da mistura por extrusão, mantendo suas propriedades mecânicas. Este resultado indica que o EPDMAE e o EPDMAG atuam como auxiliares de processamento. Palavras-chave: Borracha, reciclagem, resíduo, adesão. Effect of Modified EPDM on the Mechanical Properties and Processing of EPDM Containing EPDM WasteAbstract: This work was aimed at examining the effect from three agents in the recycling of waste rubber, namely copolymer ethylenepropylene-diene (EPDMR) containing carbon black. Three agents were prepared: EPDM modified by 1-dodecanotiol (EPDMSDD), EPDM modified by stearic acid (EPDMAE) and EPDM modified by fatty linolenic acid (EPDMAG). For the mechanical properties, the better tensile and tear strength associated with manufacturing extrusion were obtained using EPDMSDD. EPDMAE and EPDMAG improved the processing by extrusion, while keeping the mechanical properties. These results indicate that EPDMAE and EPDMAG act as auxiliary agents for processability. Keywords: Rubber, recycling, waste, adhesion. IntroduçãoOs artefatos de borrachas apresentam ampla aplicação tecnológica que se estende deste a indústria automobilística até as aplicações as hospitalares [1] . Os polímeros, de um modo geral, apresentam degradação lenta e nas borrachas (elastômeros), este fato é potencializado pela presença de ligações cruzadas e de outros aditivos presentes na composição como antioxidantes, antiozonantes e cargas que dificultam não somente a degradação, como também o seu reaproveitamento, pois afetam o processamento da mistura [2] . Uma forma de reutilização de resíduos de borracha é transformá-lo em pó, e utilizá-lo como carga em novas formulações. Este procedimento apresenta como vantagem o baixo custo, mas, de acordo com a literatura, apenas pequenas quantidades de carga, pós-uso, pode ser adicionada à borracha virgem sem causar perda de propriedades fisico-mecânicas e/ou afetar a processabilidade (viscosidade) da mistura [6] . Einstein formalizou as primeiras equações que descrevem os efeitos da presença de partículas sólidas no escoamento de fluidos e na tensão de cisalhamento baseados na mecânica do contínuo. Essas equações serviram como base matemática na elaboração de modelos para descrever sistemas concentrados [3] . PAYNE mostrou os principais efeitos da adição de cargas, como o negro de fumo e a sílica, nas propriedades reológicas. Suas pesquisas possibilitaram compreender a participação e o papel da distribuição e da dispersão de cargas na viscoelasticidade da mistura [4]