STRUCTURAL EFFECTS ON BIODEGRADATION OF ALIPHATIC POLYESTERS

Various types of aliphatic polyesters were prepared by both biosynthet ic and chemosynthetic methods, and their biodegradation tests were car ried out under aerobic conditions in the river water. Biodegradabiliti es of polyester films were evaluated by monitoring the time-dependent changes in the biochemical oxygen demand (BOD), weight loss (erosion) of polyester film, and dissolved organic carbon concentration (DOG) of test solution. The microbial copolyesters were degraded in the river water at a rapid rate, and the weight-loss- and BOD-biodegradabilities of the majority of biosynthetic polyesters were 100 % and 80+/-5 % fo r 28 days, respectively. In contrast, the biodegradabilities of chemos ynthetic polyesters were strongly dependent of the chemical structure of monomeric units.