Synthesis of High Aspect Ratio Bisphenols and Polycarbonates Incorporating Bisaryl Units

Theoretical arguments linking monomer geometries to polymer fracture strengths and melt flow properties provide the rationale for design of a series of isomeric, high-aspect ratio bisphenols and new polycarbonates. An efficient synthesis of these monomers in addition to an optimal triphosgenation-based method for the synthesis of high molecular weight polycarbonates is presented. Preparation and polymerization of o-, meta-, and p-tetraaryl bisphenol A are reported, in addition to glass transition temperatures of the new polycarbonates. In accordance with expectations, the p- and m- isomers form ductile, amorphous high-heat films, while the o-isomer produces a relatively low-Tg brittle glass.