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

A series of high molar mass aliph. homo- and co-polyesters was obtained from 1,4-butandiol and Me esters of succinic, adipic, sebacic acids, and these materials were characterised by 1H 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 compn., was investigated under controlled soil burial conditions. Film samples were also assayed to enzymic attack by lipase from Mucor miehei or from Rhizopus arrhizus. The biodegrdn. was evaluated as wt. loss and the relative normalized wt. loss rates were compared. The influence of crystallinity, molar mass, chem. structure and melting temp. upon biodegrdn. was studied. The wt. 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 com. 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.