| abstract |
PURPOSE: To obtain a biodegradable high molecular weight polymer which can be readily produced and are excellent in purity, etc., and suitable for a matrix for drugs by reacting a polyol with a polyfunctional ketene acetal. n CONSTITUTION: A biodegradable polymer has a repeating monomer unit represented by formula I (wherein (n) is an integer greater than 10; R 1 , R 2 , R 3 and R 4 are hydrocarbon groups, R 1 and R 2 being separate groups or parts of a cyclic group, R 3 and R 4 being separate groups or parts of a cyclic group; R 5 is a hydrocarbon group which is a residue of a polyol R 5 (OH)a, (a) being an integer not less than 2; R 6 is a valence bond or a hydrocarbon group; and R 7 and R 8 are each H or a hydrocarbon group). The biodegradable polymer of formula I is easily prepared without the formation of any by-products by reacting a polyol (e.g. 1,6-hexanediol) and a polyfunctional ketene acetal (e.g. compounds of formula II and III) at a relatively low temperature. n COPYRIGHT: (C)1991,JPO |