| abstract |
Cellular urethane polymers essentially free of the strong, objectionable amine odor characteristic of N-ethylmorpholine, are provided by effecting the polyurethane forming reaction in the presence of beta-tert-amino nitriles. In view of their low residual odor and effectiveness in the catalysis of the waterisocyanate reaction, the beta-amino nitriles either alone or in combination with other tertiary amines, are used with particular advantage as direct replacements for N-ethyl-morpholine in the manufacture of water-blown flexible polyurethanes, both molded and free-rise, including high-resilience foam as well as foams stabilized with either organosilicone or silicon-free organic surfactants. Especially effective for the formation of flexible polyester foam stabilized with either type of surfactant are blends of the beta-amino nitrile catalyst such as, in particular, 3-(N,N-dimethylamino)propionitrile, with dimethylethanolamine or a bis(2-(N,N-dimethylamino)alkyl)-ether. |