Precursor-Prepared Conditions and Drawing Properties of Ultrahigh-Molecular-Weight Polyethylene in Swell-Drawing Method

When Mv., 3.30×106 of ultrahigh-molecular-weight polyethylene was subjected to a swell-drawing method in which a stress in swelling was applied, conditions feasible for ultra-drawing were examined. Conditions for forming a polyethylene sheet were found to influence significantly the reduction of entanglements in pre-drawing and in subsequent drawing. The time held at a temperature for melting and the cooling time used in the formation indicated optimal points. Using polyethylene sheet formed in the optimal conditions, we were able to ultra-draw precursors that had been prepared by swelling in the temperature range of 103.5°C to 104°C and by pre-drawing 26 times. Maximal tensile strength and Young's modulus obtained in the present study were 5.3 GPa and 215 GPa, respectively.