Biodegradation of Synthetic Polymers Containing Ester Bonds

Oligomers of synthetic polymers are biodegradable, whereas only few polymers are biodegradable. Polyethylene adipate with Mn 3000 and polycaprolactone with Mn 25,000 were completely degraded by Penicillium spp. Aliphatic and alicyclic polyesters, ester type polyurethanes (I), copolyamide-esters (II) and copolyesters (III) of aliphatic and aromatic polyesters were hydrolyzed by lipases from various microorganisms and hog pancreas, and hog liver esterase. When aliphatic polyesters were used as enzyme substrates, it was found that their melting points (Tm) had a effect, in addition to their chemical structure, on biodegradability. It was assumed that the hydrogen bonds in the I, II chains and aromatic ring in the III chains, which were related to high Tm of I, II and III, influenced their biodegradation by lipases.