SYNTHESIS OF HYDROLYTICALLY DEGRADABLE AROMATIC POLYESTERS WITH LACTIDE MOIETIES

A synthetic route to higher molecular weight processable polyesters wi th bisphenol A terephthalate/isophthalate moieties and lactide moietie s which are of potential interest for tissue engineering is described. The combination of aliphatic and aromatic moieties is a promising con cept for processable polyesters with potential sites for physiological degradation and improved mechanical properties. The molecular structu re of the copolyesters prepared by melt condensation via an acid chlor ide route and incorporation of the lactide moieties by transesterifica tion of an oligo DL-lactide was confirmed by infrared, H-1 and C-13 nu clear magnetic resonance spectroscopy as well as gel permeation chroma tography. The thermal and mechanical properties of copoIyesters with d ifferent amounts of lactide moieties are reported and correlated with their composition. The reaction mechanism by transesterification was p roved by a model reaction with a physical blend of the components and the hydrolytical behavior of the copolyesters under physiological cond itions has been investigated. (C) 1997 by John Wiley & Sons, Ltd.