INVESTIGATION ON THE THERMAL BEHAVIORS AND MECHANICAL-PROPERTIES OF ULTRAHIGH MOLECULAR-WEIGHT POLYETHYLENE (UHMW-PE) FIBERS

Fibers of ultrahigh molecular weight polyethylene (UHMW-PE) were prepa red with the gel fiber drawing method, and the solvent and extraction solvent used were a general kerosene and gasoline, respectively. The t hermal behaviors and mechanical properties of the fiber were studied u sing thermal analysis, a wide-angle X-ray diffractiometer, density, th e sound orientation factor, as well as mechanical property measurement . The results showed that the morphology of macromolecular chains was changed from the folded state to an extended-chain structure with incr easing of the drawing ratio. In addition, the crystal form of the fibe r also changed. These changes were more evident while the drawing rati o exceeded 20. The tensile strength, similar to the modulus of the fib ers, increases with an increasing draw ratio in the range that we rese arched, whereas the sonic velocity orientation factor and the degree o f crystallinity increase slowly when the draw ratio is over 30. (C) 19 96 John Wiley & Sons,Inc.