Abstract: A process for preparing a thermoplastic polyurethane resin from a polydiene having terminal functional groups selected from the group consisting of hydroxy, amine, and carboxylic acid, at least one polymeric diol selected from the group consisting of polyester polyols, polyether polyols, and polycarbonate polyols, an isocyanate having an average functionality of 2, and a chain extender which comprises: (a) first reacting the polydiene and the isocyanate at 70 to 100° C. for 10 to 60 minutes, (b) adding to the reaction product of (a) the polymeric diol and reacting these components at 70 to 100° C. for 60 to 150 minutes to form a prepolymer, and (c) adding the chain extender and reacting these components at 70 to 125° C. for 1 to 24 hours to form a thermoplastic polyurethane.