Structural development of gel-spinning UHMWPE fibers through industrial hot-drawing process analyzed by small/wide-angle X-ray scattering

The ultrahigh molecular weight polyethylene (UHMWPE) fibers were obtained directly from the industrial production line. Two-step industrial hot-drawing-to-specific-drawing ratios were carried out at the temperature of 120 and 130 °C, respectively. Small-angle X-ray scattering (SAXS) measurements using synchrotron radiation were applied to study the evolution of kebab structure and the formation of shish structure. The slight increase of long period and the rapid decrease of lateral sizes indicated the destruction of original lamellae which was accomplished by chain slip resulted in the orientation of lamellae to form shish structure. The decrease of average shish length was explained that the formed new shish structure had shorter shish length than the original shish at the early stage with the high concentration of spinning solution. Wide-angle X-ray diffraction (WAXD) measurements were performed to explore the changes of the degree of orientation of the crystals. It was found that the elevated drawing temperature was benefited to the evolution of the orientational order. The DSC result confirmed the evolution of shish–kebab structure through the melting behavior.