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(C 5 Me 5 ) 2 THF 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.