(766d) The Importance of Crystalline Structure on the Tensile Properties of Uhmwpe

A.J. Pennings experimentally established a set of gel spinning conditions to produce stiff and strong ultra-high molecular weight polyethylene fibers in a series of papers that concluded slow spinning speeds and low draw ratios produce crystal morphology better suited for post drawing. Recent research has suggested that the initial structure of gel-spun fibers is irrelevant and with proper post-drawing parameters, fibers comparable to state of the art systems can be produced. In this work, we resolve the literature contradictions by utilizing a novel gel-spinning apparatus with precise control of extensional flow, and timescale properties of the spinning process. This allows for detailed analysis of the as-spun fiber in terms of conditions experienced during initial processing, specifically strain rate, and draw ratio. The crystalline structure of various as-spun fibers will be classified by small angle x-ray scattering, and correlated to the processing conditions. Post drawing and final mechanical property measurement is performed on a modified extensional rheometer. This information will provide an understanding of the effects of gel-spinning on fiber morphology and mechanical properties, and to answer if certain gel-spun fibers produce superior post drawn fibers.