a novel aliphatic diisocyanate , namely 1 , 4 - biscyclohexane , is disclosed . polyurethanes derived from this diisocyanate exhibit advantageous properties . illustratively , polyurethane elastomers prepared from the above diisocyanate , a polymeric diol and a low molecular weight diol extender , possess significantly improved resilience properties and are useful in the preparation of automobile bumpers , fenders and the like .