Thermal and mechanical properties of mandelic acid-copolymerized poly(butylene succinate) and poly(ethylene adipate)

Phenyl side chains were introduced to poly(butylene succinate) and poly(eth ylene adipate) by the polymerization of the respective monomers in the pres ence of mandelic acid. The increasing content of the phenyl side chains dec reased the melting temperature and the crystallinity but increased the glas s-transition temperature of the aliphatic polyesters. The phenyl side branc hes reduced the crystallinity of poly(butylene succinate) more significantl y than the ethyl or n-octyl side branches did. The tensile strength, elonga tion, and tear strength of poly(ethylene adipate) decreased with an increas e in the content of mandelic acid units. However, the increasing content of mandelic acid units enhanced the elongation and tear strength of poly(buty lene succinate) considerably without a notable deterioration of tensile str ength. The biodegradability of the copolyesters was increased as a result o f the introduction of more mandelic acid units due to the decrease in the c rystallinity. (C) 2000 John Wiley & Sons, Inc.