Melt-processible poly(ester urethane) and a process for the preparation thereof

PCT No. PCT/FI95/00396 Sec. 371 Date Jan. 31, 1997 Sec. 102(e) Date Jan. 31, 1997 PCT Filed Jul. 7, 1995 PCT Pub. No. WO96/01863 PCT Pub. Date Jan. 25, 1996The invention concerns a novel melt-processible poly(ester urethane) and a process and a prepolymer for the preparation thereof. The poly(ester urethane) contains structural units derived from a polyester and structural units derived from a diisocyanate and, according to the invention, the bonds between the structural units are at least mainly comprised of urethane bonds, the number average molar mass, Mn, of the prepolymer is at least 10,000 g/mol, its mass-average molar mass, Mw, is over 20,000 g/mol and its molar mass distribution, expressed as the ratio of Mw/Mn, is over 2, and the prepolymer is essentially free from free isocyanate groups. The poly(ester urethane) is hydrolytically decomposable and it can be used as a biodegradable polymer, e.g., for manufacturing injection molded pieces and thermoformed and blow molded packages, bags, sacks and bottles, for coating of sacks, bags and films made of paper or cardboard, and for manufacturing fibers and non-woven fabrics.