The present invention is to the preparation and application of isocyanate based polymers, particularly polyurea elastomeric polymers. By incorporating polybutadiene with a natural oil based polyol in a thermoplastic system, particularly in the formation of a prepolymer the produced elastomer display good chemical resistance. Such prepolymers are an isocyanate terminate prepolymer wherein the polyol composition for the production of the prepolymer comprises a polybutadiene polyol and a natural oil based polyol.