ABSTRACT
The development of polycarbonate thermoplastic resins evolved as a subset of general polyester chemistry. Since Einhorn's initial solution preparation of resorcinol-and hydroquinone-derived polycarbonates in 1898 [1], research has focused on efficient resin preparation and material properties. This seminal synthetic work used phosgene in a pyridine solution. Einhorn's phosgene procedure was followed in 1902, by the development of a melt transesterification method. Using diphenyl carbonate (DPC) as a phosgene synthon, Bischoff and v. Hedenstroem produced the same materials obtained by Einhorn [2]. Due to the poor solubility of these early resins, the general difficulty in their manipulation (processing), and the limited methods of material characterization available, interest in aromatic polycarbonates waned.
