Abstract: The invention relates to the field of crosslinkable thermoplastic polyurethane resins containing ethylenic side groups.This resin preferably results from the reaction of (a) an organic diisocyanate, (b) a saturated linear diol, (c) a diol having a molecular weight of less than 300, and (d) an unsaturated diol consisting of the acrylic or methacrylic acid ester of a trihydric alcohol, of the formula: ##STR1## in which R.sub.3 =Me or H and n is an integer between 1 and 4. 2,3-Dihydroxypropyl acrylate will preferably be used.The polyurethane resin according to the invention can be processed in accordance with the well-known traditional processes for thermoplastics, while at the same time being capable of undergoing crosslinking, by virtue of their unsaturated side groups, to form a three-dimensional lattice.Application to profiles and prepregs.