The effect of shrinkage on the structure and properties of ultra-high molecular weight polyethylene fibers with different concentration

摘要

Interface variation in the extraction and drying process of ultra-high molecular weight polyethylene (UHMWPE) gel fiber results in different shrinkage at different direction. The essence of shrinkage lies in the crystallization of UHMWPE chains under the effect of interface tension. However, UHMWPE gel fiber prepared with different solution concentration has different chain entanglement points density that can hinder the regular stacking for UHMWPE chains. The restriction for axis shrinkage of UHMWPE gel fiber facilitates the orientation of UHMWPE chains that is beneficial to improve the tensile strength of UHMWPE drawn fiber. Combined with multiple methods of Wide angle X-ray diffraction, Small-angle X-ray scattering, Differential scanning calorimetry and sonic orientation, the structural evolution of UHMWPE fiber with different shrinkage ratio and different concentration was investigated. Meanwhile, the suitability for UHMWPE fibers in production was evaluated by final tensile strength of the fibers. Here, a structural evolution model is proposed to elucidate the correlation between the shrinkage and the structure and properties of UHMWPE fibers prepared with different solution concentration.