ABSTRACT
This chapter discusses the name for the new family of amorphous high-heat polycarbonates abbreviated as Polycarbonate-Heat-ageing (PC-HT). The former concept was applied in the development of tetramethyl bisphenol A polycarbonate. Polycarbonates from bisphenol TMC can be produced by the same methods and in the same production units which are suitable for bisphenol A polycarbonates. A method of choice is an interfacial condensation process, in which phosgene is reacted with the sodium salts of the aromatic diols in the presence of tertiary amine catalysts. Cocondensation with bisphenol A yields statistical copolycarbonates. The development of PC-HT resins originated from the demand for higher heat resistance in applications, which extended beyond the limits of standard PC. PC-HT applications can be classified by the duration of heat exposure and can be roughly and somewhat arbitrarily divided into the following service categories: long-term heat, mid-term heat, short-term heat and no heat.
