ABSTRACT
This chapter shows that synthetic aliphatic polyesters are hydrolyzed by several commercial lipases and hog liver esterase. To find both new biodegradable synthetic polymers and the reasons why aromatic polyesters and polyamides are not biodegradable, the authors synthesized copolyesters (CPE) and copolyamide-esters (CPAE) and studied their susceptibility to hydrolysis by lipase. Hydrolysis of solid polymers was measured by the rate of solubilization, and measurement did not necessarily involve complete hydrolysis into constituent parts. Number average molecular weight was measured by the vapor pressure equilibrium method using Hitachi Molecular Weight apparatus. The polymerization degree of each block was determined from the position of the peak top on each CPC chromatogram. The susceptibility of CPAEs to hydrolysis by Rhizopus delemar lipase decreased with shortening of the polyamide blocks and increasing polyamide content. The new biodegradable synthetic polymer, CPAE, can be made into any desired shape.
