Research on the molecular entanglement and disentanglement in the dry spinning process of UHMWPE/decalin solution

摘要

The macromolecular entanglement and disentanglement in the dry spinning process of ultrahigh molecular weight polyethylene (UHMWPE)/decalin solution were investigated. By the fitting results of the theoretical model to the experimental data, it is found that the variation tendency of the N(s)kT value, which reflects the chain slippage at the slip links in the extensional deformation on spinning line of draw-down process, is in accordance with the fact that each of the relationship curves between the tensile strength, modulus of the UHMWPE fibers through maximized solid state drawing and the draw-down ratio showed a peak, thus discovering the molecular movement mechanism of "disentanglement on spinning line." When the entanglements were included in the flow units, their apparent quantity would decrease. Based on this result, the optimum draw-down ratio can be determined directly by measuring the draw-down stress at the exit of the spinning duct. The molecular entanglements numbers, which are derived from the theoretical fitting to the experimental data of predrawing and after-drawing process, abruptly increased in large amounts. It may be concluded that these are mainly not attributed to the topological entanglements, but attributed to the agglomerate entanglements. (c) 2006 Wiley Periodicals, Inc.