Disentanglement and Degradation During Dissolving Process and Their Effect on the Tensile Properties of <scp>UHMWPE</scp> Fibers

ABSTRACT Ultrahigh molecular weight polyethylene (UHMWPE) fibers were prepared using the gel spinning‐ultra drawing method. Generally, the spinning solution is prepared by dissolving UHMWPE in its solvent at high temperature under severe shearing using a twin‐screw extruder, which helps to disentangle UHMWPE chains in the solution. In this article, the effects of spinning solution concentration and twin‐screw extruder dissolving temperature on the degree of disentanglement and degradation of UHMWPE chains, as well as the fiber structure and tensile properties, were explored. The results showed that a lower concentration of UHMWPE had better dissolution and disentanglement results, and the molecular degradation was less, resulting in higher tensile properties of the obtained UHMWPE fibers. However, the effect of dissolving temperature on the tensile properties of fibers was complex. On one hand, the increase in dissolving temperature increased the degree of UHMWPE disentanglement. On the other hand, an excessively high temperature exacerbated the UHMWPE degradation. Only at an appropriate dissolving temperature can the balance between sufficient UHMWPE disentanglement and low degradation be reached, and then UHMWPE fibers with excellent tensile properties can be obtained.