catalyst; [0089] (3) Polyurethanes, such as those prepared from polyols and diisocyanates or polyisocyanates and those disclosed in U.S. Patent No. 5,334,673; [0090] (4) Polyureas, such as those disclosed in U.S. Pat. No. 5,484,870; [0091] (5) Polyamides, such as poly(hexamethylene adipamide) and others prepared from diamines and dibasic acids, as well as those from amino acids such as poly(capro