Estudo da dispersão, localização seletiva e efeito compatibilizante de argila montmorilonita em blendas poliméricas de policarbonato/SAN

Abstract

The present study investigated the compatibilization effect and stabilization on the morphology of polycarbonate/styrene-acrylonitrile blends (PC / SAN) by incorporating montmorillonite clay. A systematic study was realized by incorporating different clay concentrations in PC/SAN blends with fixed composition of 70/30 %wt respectively. Polymer blends were processed by extrusion / injection and the thermal aging was performed in order to evaluate the morphological stability. We also investigated the effects of acrylonitrile content and different organic modifier present in clays 20A, with low polarity and 30B clay, which has high polarity, in mophology development of morphology in PC/SAN blends. Transmission electron microscopy (TEM) analysis indicated that the presence of clay significantly improved the morphological stability and significantly changed the morphological behavior of the blends even with only 1% wt of clay. In fact, 20A clay showed better results due to its preferential location at the blendsinterfase. On the other hand, 30B clay migrated to the interior of the dispersed phase due to better interaction of SAN and 30B clay modifier. The increase in the acrylonitrile content of the SAN reduces the effect of compatibilizing/stabilizing morphology because it favors greater interaction between SAN/clay that confined clay particles in SAN phase. The analysis of Xray diffraction indicated intercalated structures for nanocomposites obtained from 20A clay and intercalated/exfoliated for nanocomposites obtained from 30B clay.In addition, it was observed evidence of degradation and collapse of clay galleries from 30B nanocomposites. DSC and DMTA analysis showed a reduction in glass transition temperature (Tg) of the PC rich phase proportionally to clay content.