SYNTHESIS AND BIODEGRADATION OF THE COPOL YMERS OF SUCCINIC ANHYDRIDEWITH VARIOUS OXIRANES

The ring-opening copolymerization of succinic anhydride with various o xiranes by organometalic compounds (diethyl zinc, Al2-Zn-mu-oxoalkoxid e, and aluminium isopropoxide) and the biodegradability of the produce d polymers were investigated. The initiator influenced the molecular w eight and the composition of these copolymers. Random copolymers were produced by diethyl zinc. The molecular weight of these copolymers wer e larger than those of copolymers obtained using other initiators. Alu minium isopropoxide gave alternative copolymers of succinic anhydride with oxirane. The amount of initiator affected the molecular weight of these copolymers. The copolymers of succinic anhydride with ethylene oxide were crystalline, while the copolymers with propylene oxide were amorphous. The biodegradation values of the copolymers were evaluated by an enzymatic hydrolysis method. The aliphatic copolymers of succin ic anhydride with ethylene oxide, propylene oxide or allyl glycydil et her were readily degraded by a lipase. However, the aromatic copolymer s produced from succinic anhydride with styrene oxide or phenyl glycyd il ether were little degraded. The degradation can be controlled by th e ester content and molecular weight of these copolymers.