Blendas de PMMA e AES : morfologia e propriedades mecanicas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

In this work blends of the poly(methyl methacrylate), PMMA, and of the AES elastomer were prepared. AES is a elastomer obtained from grafting of the poly(styrene-co-acrylonitrile), SAN, on the poly(ethylene-co-propilene-2-etiliden- 5-norbonene), EPDM. The EPDM phase of the AES is immiscible and incompatible with PMMA, while the phase SAN is miscible one. The blends were prepared in a single screw extruder and in an internal mixer in compositions containing 5 wt %, 10 wt %, 20 wt % and 30 % of AES. It was also prepared a blend containing 20 wt% of EPDM. The morphology was investigated by scanning electron microscopy; the mechanical properties by tensile, flexure and impact resistance tests and the miscibility between SAN and PMMA by differential scanning calorimetry and dynamic mechanical analysis. The results showed the miscibility between PMMA and SAN, which is responsible for the good interfacial adhesion in the blends and the good mechanical properties of the blends. The elongation at break and the impact resistance increased more than 300% and 800%, respectively, for the blends containing 30 wt% of AES in comparison to PMMA, with a lost of 30% of the modulus and maximum tension values. The EPDM blend presented the worse mechanical properties, due to the low interfacial adhesion. This result demonstrated the role of the SAN phase of the AES to improve the interfacial adhesion and mechanical properties. The processing conditions also influenced the morphology and consequently the mechanical properties of the blends.

ASSUNTO(S)

morfologia blendas - propriedades mecanicas blendas

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