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

Abstract

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