Biodegradations of statistical copolymers composed of D,L-lactide and cyclic carbonates

Syntheses and biodegradation of statistical copolymers of D,L-lactide (D,L-LA) with trimethylene carbonate (TMC), rac-1-methyltrimethylene carbonate (1-MTMC) and 2,2-dimethyltrimethylene carbonate (2,2-DTMC) were investigated at various monomer ratios using SmMe(C₅Me₅)₂THF as an initiator at 80 °C for 24 h in toluene. Biodegradations of poly(D,L-LA-co-racemo-1-MTMC) (95/5) and poly(D,L-LA-co-2,2-DTMC) (98/2) with a compost at 60 °C proceed rapidly. Enzymatic degradations of these polymers were also performed using cholesterol esterase, lipoprotein lipase and proteinase K. Only poly(D,L-LA-co-TMC) was biodegraded with cholesterol esterase, while poly(TMC), poly(1-MTMC), poly(2,2-DTMC) and poly(D,L-LA) were barely degraded with these enzymes. Biodegradations of poly(D,L-LA-co-TMC) (87/13) and poly(D,L-LA-co-racemo-1-MTMC) (95/5) are rapid using proteinase K. Physical properties of these copolymers were also described.
© 2003 Society of Chemical Industry