Abstract: This invention concerns a process for improving the hydrolysis resistance of urethane elastomers, a polyester polyol for implementing this process, the urethane elastomer obtained by this process, and its use.

Abstract: This invention concerns a process for improving the hydrolysis resistance of urethane elastomers, a polyester polyol for implementing this process, the urethane elastomer obtained by this process, and its use.

Abstract: The invention concerns a method for making a polyurethane foam by reacting at least a polyester polyol with at least a polyisocyanate in the presence of a foaming agent and a catalytic agent, such a polyester polyol having been previously obtained by reacting a reactive acid A comprising at least an aliphatic or aromatic polyacid with functionality not less than 2 with at least a polyol P2 with functionality equal to 2 and at least an aliphatic or aromatic polyacid with functionality not less than 2 with at least a polyol P2 with functionality equal to 2 and at least a polyol P3 with functionality not less than 3, being thereafter called AP2P3, wherein the catalytic agent at least partly consists of at least one amine polyester polyol AP2P3, wherein at least part of polyol P3 consists of at least a polyoxyalkylene polyalkanolamine having at least a tertiary amine function, the alkanol radicals of said polyalkanolamine being C1-C6, the alkylene oxide units being C2-C4 and the statistical mean of the number N o

Abstract: Process for the preparation of polyester-polyurethane flexible foams which do not give rise to the formation of misting, in which at least one polyisocyanate is reacted with at least one polyester pretreated by distillation and water and/or highly volatile organic compounds as blowing agent, characterized in that, in order to obtain the pretreated polyester which is used in the reaction with the polyisocyanate, in a first stage a starting polyester is manufactured which has a hydroxyl value (HV) higher by 4 to 12 mg KOH/g in relation to the HV of the desired pretreated polyester and which has a viscosity, measured at 25.degree. C. with a Brookfield RVT viscometer, lower by 2 to 5 Pa s in relation to that of the desired pretreated polyester and, in a second stage, the said starting polyester is subjected to a distillation for a treatment period of between 2 and 300 seconds, in temperature and pressure conditions making it possible to extract at least 85% of the cyclic diester present in the starting polyester.