Spandex elastomers

摘要

Spandex-type polyurethane/urea segmented elastomers with exceptional physical properties may be prepared by the aliphatic and/or cycloaliphatic diamine chain extension of a solution of isocyanate-terminated polyoxypropylene diol-derived prepolymer wherein the diol component comprises in major part an ultra-low unsaturation polyoxypropylene diol having an unsaturation of less than about 0.010 meq/g and a number average molecular weight greater than 2000 Da. The spandex polymers have commercially desirable percent set and are capable of exceeding the properties of the industry standard PTMEG elastomers in many respects, particularly in elongation and hysteresis.