PREPARATION OF HIGH-STRENGTH AND HIGH-MODULUS POLY(VINYL ALCOHOL) FIBERS BY CROSS-LINKING WET SPINNING MULTISTEP DRAWING METHOD

This study is mainly focused on the preparation of high-strength and high-modulus poly(vinyl alcohol) (PVA) fibers by crosslinking wet spinning and multistep drawing. High strength as well as high modulus can be achieved by introduction of the crosslinks into the oriented chains to reduce entanglement degree and slippage between chains. The relationships between mechanical properties and fine structure of the drawn fibers were examined based on results of measurements of tensile property, thermal property, dynamic viscoelasticity, crystallinity, and orientation. The strength and Young's modulus of the drawn fibers are approximated to 1.82 and 51.76 GPa, respectively. The fiber has a sharp melting peak temperature that appeared at 236.7-degrees-C in the differential scanning calorimeter (DSC) curve. Our results indicate the multistep drawing procedure is superior to the conventional one-step drawing procedure. These excellent mechanical properties can be directly attributed to their high orientation of the amorphous chains. (C) 1994 John Wiley & Sons, Inc.