Spandex from poly(tetramethylene-co- ethyleneether)glycols blended with polymeric glycols
A polyurethaneurea composition comprises a reaction product of at least one diisocyanate compound, a polymeric glycol, a poly(tetramethylene-co-ethyleneether) glycol comprising constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide (EO) wherein the portion of the constituent units derived from ethylene oxide is present in the poly(tetramethylene-co-ethyleneether) glycol from greater than about 37 to about 70 mole percent, at least one diamine chain extender, and at least one chain terminator. The invention further relates to the use of blends of polymeric glycols and poly(tetramethylene-co-ethyleneether) glycols as the soft segment base in spandex compositions. The invention also relates to new polyurethane compositions comprising polymeric glycols and poly(tetramethylene-co-ethyleneether) glycols, and their use in spandex.
1. A spandex comprising polyurethaneurea comprising a reaction product of:
(a) a poly(tetramethylene-co-ethyleneether) glycol comprising constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly(tetramethylene-co-ethyleneether) glycol from greater than 37 to 49 mole percent and wherein the poly(tetramethylene-co-ethyleneether) glycol has a molecular weight ranging from 2049 to 2535 Daltons;
(b) a poly(tetramethylene ether) glycol having a molecular weight of 1800 Daltons;
(c) at least one diisocyanate selected from the group consisting of 1-isocyanato-4-[(4-isocyanato-phenyl)methyl]benzene, 1-isocyanato-2-[(4-isocyanato-phenyl)methyl]benzene, and mixtures thereof; and
(d) a mixture of ethylenediamine and diethylamine;
wherein the poly(tetramethylene-co-ethyleneether) glycol and the poly(tetramethylene ether) glycol are blended into a mixture having an average of 27 mole percent of units derived from ethylene oxide and a molecular weight of 1936 to 2253, and wherein said spandex exhibits lower first cycle load power, stress decay and percent set and greater tenacity and higher unload power at 100% elongation as compared to poly(tetramethylene-co-ethyleneether) glycol-based spandex with the same ethyleneether content prepared from poly(tetramethylene-co-ethylene ether) glycol having a molecular weight of about 2045 Dalton without a poly(tetramethylene ether) glycol.
2. A fabric comprising the spandex of claim 1 .
3. A garment or textile article comprising the fabric of claim 2 .