| 摘要 |
1,258,593. Polyurethanes. E. I. DU PONT DE NEMOURS & CO. 28 May, 1969 [31 May, 1970], No. 27031/69. Heading C3R. Long chain elastomeric polyether-based segmented polyurethanes containing in the polymer chain tertiary amine nitrogen bonded to two non-carbonyl carbon atoms and further bonded to a t-butyl group, the polyurethane containing at least 10 milliequivalents of such nitrogen per kilogram of polyurethane may be prepared by reacting a polyether glycol, an organic diisocyanate a chain extender and optionally a chain-terminating amine, at least one of these compounds containing a tertiary amine nitrogen bonded to two non-carbonyl carbon atoms and further bonded to a t-butyl group. The N-t-butyl groups may suitably be incorporated in the reaction mixture by chain extending polyether-based prepolymers with N-t-butyl-diethanolamine, 4-t-butyl-4-aza-2,6- heptanediol, N - t - butyl - diethylene triamine or 4 - t - butyl - 4 - aza - 2,6 - diamino - heptane. Conventional chain extenders e.g. organic diamines, hydrazine and dihydrazides may be incorporated in the reaction mixture. |
