SYNDIOTACTICITY-RICH POLY(VINYL ALCOHOL) FIBERS SPUN FROM N-METHYLMORPHOLINE-N-OXIDE WATER MIXTURE/

Aqueous NMMO solutions containing NMMO above 50% are good solvents for syndiotacticity-rich poly(vinyl alcohol) (s-PVA). Although water is n ot a good solvent and dissolves s-PVA at temperatures above 100 degree s C, the mixtures dissolve it at temperatures below 100 degrees C. s-P VA fibers were prepared through gel-spinning of s-PVA/NMMO/water (NMMO : water = 70 : 30) mixtures in cold water and wet-spinning of the sol ution in methanol. The mechanical properties and fine structure of the drawn fibers were examined based on the results of measurements of te nsile properties, thermal properties, birefringence, and optical and e lectron microscopic observations. The strength and Young's modulus of the drawn fibers were approximately to 2.0 and 45 GPa, respectively. T he reason why the fibers with theoretical mechanical properties could not be prepared was surmised to be related to the structure of the amo rphous regions. (C) 1996 John Wiley & Sons, Inc.