ARCHITECTURE OF BIODEGRADABLE COPOLYESTERS CONTAINING AROMATIC CONSTITUENTS

Aliphatic/aromatic copolyesters, especially those synthesized from but anediol, adipic acid and terephthalic acid, have been shown to represe nt biodegradable plastics of high commercial interest. Within a range of approx. 30-55 mol% terephthalic acid in the acid components such co polymers are an acceptable compromise between use properties and degra dation rate. The behaviour of aromatic intermediates has been examined by use of specially synthesized aromatic model oligomers. Oligomers w ith a degree of polymerization of one and two are rapidly degraded by microorganisms; for longer oligomers, only a chemical hydrolysis is po stulated at higher temperatures. By means of enzymatic hydrolysis of m onomeric model esters with a lipase it was shown that the rigidity, es pecially of the diacid component, influences the accessibility of the ester bonds to the action of the lipase. (C) 1998 Elsevier Science Lim ited. All rights reserved.