| 摘要 |
This disclosure relates to a process for the preparation of thermoplastic urethane polymers or elastomers also having urethane and urea linkages derived by the reaction of the adduct of 6-caprolactam and an alkylene diamine, this adduct having the formula NH2(CH2)5CONH(CH2)xNH2 in which x has a value of 2-8, with a urethane prepolymer. The resulting urethane-urea elastomer has improved properties in comparison with such elastomers prepared from urethane prepolymers and 4,4'-methylene-bis-2-chloroaniline, generally referred to as "MOCA", or lauroguanamine which are the commonly used diamines for such purpose. In addition to the improved properties compared to the elastomers prepared from MOCA and aliphatic diamines, the product of this process has a considerably longer pot life and the reaction can be carried out at relatively elevated temperatures without gel formation. These elastomers are suitable for preparing melt-spun spandex fibers of high tenacity and melting temperature.
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