Coordination polymerization of lactides, 1. Structure determination of obtained polymers

Abstract

Abstract Racemic lactide was polymerized with various initiators containing Zn and Al, and the structures of the obtained polymers were determined by means of 13 C NMR spectroscopy. The extent of transesterification reactions was calculated on the basis of the analysis of the methine carbon signal in the polymer 13 C NMR spectra. Three groups of initiators can be distinguished in view of their influence on transesterification: ZnCl 2 exhibits the strongest transesterification activity, ZnEt 2 and ZnEt 2 /Al(OiPr) 3 are among those of medium activity, and Al(acac) 3 does not show transesterification activity at all.