Abstract: The invention relates to the use of absorbable physiologically acceptable sheets of copolymers for preventing postoperative adhesions after surgical procedures and is characterized in that the sheets consist of racemic lactide and .epsilon.-caprolactone, .sigma.-valerolactone, .tau.-decalactone or .beta.-hydroxybutyric acid, prepared by reacting the monomers in the molar ratio of lactide to partner in the reaction of from 90 to 70 30 to 10 with the addition of metal carboxylates which are known per se as initiator, with a ratio of partner in the reaction to initiator of from 300:1 to more than 1000:1 at temperatures of 130.degree.-150.degree. C. over a period of 24 to 96 hours.