Spandex elastomers

A process for increasing throughput in the preparation of films or fibers of segmented polyurethane/urea spandex elastomers by extrusion of a segmented polyurethane/urea spandex polymer dissolved in a polar aprotic solvent, said solution having a maximum effective processing viscosity, said process comprising selecting as said segmented polyurethane/urea spandex polymer a diamine chain-extended isocyanate-terminated prepolymer prepared by reacting an excess of one or more di- or polyisocyanates with a polyol component comprising a high molecular weight polyol portion comprising one or more ultra-low unsaturation polyoxypropylene glycols, said high molecular weight polyol portion having a number average molecular weight of about 1500 Da or more, and a low molecular weight diol portion, said low molecular weight diol portion having a number average molecular weight of about 750 Da or less, wherein said spandex polymer solution has a solution viscosity which is at least 50% lower than a PTMEG-derived segmented polyurethane/urea polymer solution containing a PTMEG-derived segmented polyurethane/urea polymer prepared from the same components as said segmented polyurethane/urea spandex polymer except that said polyol component is replaced by a 2000 Da molecular weight PTMEG, both viscosities measured at 20 weight percent solids at 25.degree. C., and increasing said solids content of said polyurethane/urea spandex polymer in said solution to a solids content higher than the solids content of said PTMEG-derived segmented polyurethane/urea contained in said solution having a maximum effective processing viscosity to provide a solution viscosity less than or equal to said maximum effective processing viscosity.