IMPROVED SPANDEX ELASTOMERS

摘要

Spandex-type segmented polyurethane/urea elastomers having improved physical properties are prepared by the amine chain extension of an isocyanateterminated prepolymer prepared by the reaction of a stoichiometric excess of isocyanate with a polyol component containing at least one ultra-low unsaturation polyoxypropylene glycol with an unsaturation of less than about 0.010 mek/g and a molecular weight of more than about 1,500 Da. The ultra-low unsaturation polyoxypropylene glycol may be used in admixture with polytetra methylene ether glycol and/or a low molecular weight diol to form the polyol component. In the absence of low molecular weight diol, the ultra-low unsaturation polyoxypropylene glycol and the polyol component should have molecular weights of at least 2,500 Da and at least 2,000 Da, respectively.