Patent ID: 7671164
Filing Date: 2010-03-02
Classification: C08G

Abstract:
1. A method for the manufacture of an aliphatic polycarbonate, comprising: melt reacting an ester-substituted diaryl carbonate of the formula: wherein with a multifunctional compound of the formula: wherein to form a first oligomer having a weight average molecular weight of 4,000 to 12,000 g/mol, measured using gel permeation chromatography using polystyrene standards, and comprising less than 2,000 ppm of an ester-linked terminal group of the formula: wherein each R 5 is independently a halogen atom, cyano group, nitro group, C 1-20 aliphatic group, C 4-20 cycloaliphatic group, or C 6-18 aromatic group, and f is 0 to 4, as determined by 1 H NMR; and melt polymerizing the first oligomer in the presence of a transesterification catalyst to form the aliphatic polycarbonate.