Process for producing substantially linear carbonate polymer

Abstract

In the preparation of a substantially linear carbonate polymer wherein carbonic dihalide is introduced to a substantially anhydrous solution comprising at least one substituted or unsubstituted 1,3-propanediol, the coproduction of cyclic carbonate is reduced by the presence in the solution of a catalytic amount of nitrogen-containing, hydrohalide salt-forming, thermally regenerable organic catalyst. The preferred carbonic dihalide is phosgene and the preferred catalyst is pyridine.

Dependencies are inferred from the claim text.