Use of tertiary aliphatic monocarboxylic acids as chain terminators for the preparation of polycarbonates and polyestercarbonates

摘要

The use of tert., aliphatic monocarboxylic acids (I) as chain cleavage agents for the prodn. of thermoplastic aromatic polycarbonates (PC) and polyester-polycarbonates (PES-PC) is claimed. Also claimed are (1) prepn. of PC from diphenols, phosgene and opt. chain branchers; (2) prepn. of PES-PC from diphenols, phosgene, aromatic dicarboxylic acid derivs. and opt. chain branchers, by the interfacial polycondensation method, in each case using 0.6-10 mole% (I) as chain cleavage agent (w.r.t. no. of moles diphenol); and (3) PC with tert. aliphatic monocarboxy end gps., and PES-PC with mean mol. wts. (Mw by GPC analysis) of 5000-200,000 and tert. aliphatic monocarboxy end gps., both obtd. by this process.