Soil burial and enzymatic degradation in solution of aliphatic co-polyesters

A series of high molar mass aliphatic homo- and co-polyesters was obtained from 1,4-butandiol and methyl esters of succinic, adipic, sebacic acids, and these materials were characterised by H-1 NMR, SEC, DSC, X-ray and viscosity. Good filmability was achieved for all the polymers. The biodegradability of poly(butylene succinate-co-butylene sebacate), P(BSu-co-BSe), and poly(butylene succinate-co-butylene adipate), P(BSu-co-BAd), samples, with different composition, was investigated under controlled soil burial conditions. Film samples were also assayed to enzymatic attack by lipase from Mucor miehei or from Rhizopus arrhizus. The biodegradation was evaluated as weight loss and the relative normalised weight loss rates were compared. The influence of crystallinity, molar mass, chemical structure and melting temperature upon biodegradation was studied. The weight loss of poly(3-hydroxy butyrate), P(HB), of poly(3-hydroxy butyrate-co-3-hydroxy valerate) 76/24, P(HB-co-HV) 76/24, and of two commercial Bionolle samples, was also investigated under soil burial conditions. The results allow a direct comparison of the soil burial degradability of polyesters having different structures. (C) 2004 Elsevier Ltd. All rights reserved.