Abstract: A polyurethane and/or polyurethane urea elastomer in the form of a thermostable processable melt, which is immediately processable or which, after cooling and storing, can be remelted and processed. The elastomer is produced by a polyaddition or build-up reaction of longer chain diols with diisocyanate, chain extenders and a polar gelling and/or melting aid for the formation of the thermostable processable melt. A method for manufacturing a polyurethane and/or polyurethane-urea elastomer in the form of a thermally stable processable melt which may be processed immediately or after cooling and storage, being remeltable and reprocessable. The method comprises the steps of: converting n-Mol of a polymeric diol to form a prepolymer with about 1.1 to about 10.0 n-Mol of a diisocyanate at about 50.degree. C. to about 150.degree. C.