Novel polymers are represented by general formula (I) :
wherein R1 represents tetramethylene, methyltetramethylene, pentamethylene, 1,4-dimethyl-2-oxo-3- oxytetramethylene, 2-oxo-3-oxytetramethylene or 2-methyl-3-oxypentamethylene, and m and n each represents a natural number of from 10 to 15,000.
Preferably the ratio of units (III) to (IV) is 99 :1 to 1 :99 and the weight average molecular weight is 8,000 to 1,000,000.
Industrial production is by subjecting optically active β-butyrolactone and a six- or seven-membered lactone to ring-opening copolymerization in the presence of a catalyst, preferably a distannoxane.
The polymers have optical activity, biodegradability (e.g. enzymatic), and hydrolyzability.
新型聚合物由通式 (I) 表示:
其中 R1 代表四亚甲基、甲基四亚甲基、五亚甲基、1,
4-二甲基-2-氧代-3-氧代四亚甲基、2-氧代-3-氧代四亚甲基或 2-甲基-3-氧代五亚甲基,m 和 n 各代表 10 至 15,000 的自然数。
单元(III)和(IV)的比例最好为 99:1 至 1:99,重量平均分子量为 8,000 至 1,000,000。
工业化生产是将具有光学活性的
β-丁内酯和六元或七元内酯在催化剂(最好是二烷氧基)存在下进行开环共聚。
这种聚合物具有光学活性、
生物降解性(如酶解)和
水解性。