Abstract: The invention relates to highly reactive polyoxyalkylene-polyols prepared by oxyalkylation of an initiator molecule containing, in bonded form, at least 2 reactive hydrogen atoms and at least one tertiary amino group bonded via a spacer bridge, which preferably comprises an alkylene radical having at least 3 carbon atoms, by means of at least one alkylene oxide, preferably ethylene oxide and/or 1,2-propylene oxide, to a process for the preparation of these polyoxyalkylene-polyols, and to their use for the production of compact or cellular, preferably flexible polyisocyanate polyaddition products.

Abstract: A composite element which comprisesA) at least one top layer of polyvinyl chloride or a polyvinyl chloride-containing polymer mixture, andB) a preferably semirigid or rigid polyurethane foam, the top layer (A) or the polyurethane foam (B) or the two constituents (A) and (B) containing units of an .alpha.,.beta.-olefinically unsaturated polyester having a molecular weight factor per double bond of from 150 to 3000,a process for the production of composite elements of this type, and liquid, urethane-containing polyisocyanate mixtures based on diphenylmethane diisocyanates and higher homologs thereof and .alpha.,.beta.-olefinically unsaturated polyesters for the preparation of the polyurethane foam (B) are described.