Compatibility of Statistical Aromatic Copolycarbonates in Polystyrene and Poly(carbonate of Bisphenol A) Blends

Abstract

In this work the compatibility of aromatic copolycarbonates containing\ud bisphenol A (BPA) and tetramethyl bisphenol A (TMBPA) with polystyrene (PS) was\ud investigated. Miscibility prediction data were used to select copolycarbonates of\ud potential interest for developing highly compatible blends. Statistical\ud copolycarbonates (CPCs) containing different BPA/TMBPA molar ratios were\ud synthesized by polycondensation reaction and the effect of copolymer composition\ud on the PS/CPC miscibility was studied. The blends were prepared by casting from\ud chloroform solutions and/or melt mixing. The compatibility was evaluated by\ud optical microscopy (OM), calorimetric (DSC), and dynamic-mechanical thermal (DMTA)\ud analyses. Two glass transition temperatures were found for all the prepared PS/CPC\ud blends, but an improvement of compatibility was obtained increasing TMBPA content\ud in CPC copolymer. On the other hand, blends of polycarbonate of bisphenol A (PCPA)\ud and CPCs were characterized by a single glass transition temperature and\ud transesterification reaction was noticed. Finally, a compatibilization effect of\ud CPCs and polycarbonate of tetramethyl-bisphenol A (PCTMP) was highlighted in\ud PS/PCPA/CPCs and PS/PCPA/PCTMP three components blends