| Abstract: | The types and concentrations of end groups present in bisphenol A-tetrabromobisphenol A copolycarbonates (BA-TBBA coPCs) have major effects on the copolymer solution washability and thermal stability. Six types of coPC end groups are possible: two by monophenol capping of each comonomer, two phenolics (BA-OH and TBBA-OH), and two carbamates (one from each comonomer). BA-TBBA coPCs were prepared by typical solution and interfacial methods and their phenolic and carbamate end group concentrations were correlated with their solution washability and thermal discoloration. Both phenolic and carbamate end groups proved deleterious to these two copolymer properties. An improved interfacial process that employs 4-N,N-dimethylaminopyridine as the coupling catalyst provides coPCs having low concentrations of phenolic and carbamate end groups and that, therefore, wash without emulsification and are thermally stable. © 1994 John Wiley & Sons, Inc. |
