Residual Solvent in Highly Oriented Ultrahigh Molecular Weight Polyethylene Fibers

The use of a solvent, Vaseline oil, for the orientational drawing of high-strength and high-modulus UHMWPE fibers is considered. Since the side effect of the residual solvent during orientational drawing of UHMWPE fibers is the formation of pores that reduce the packing density of macromolecules, then at a certain stage of drawing the fiber, the solvent is removed from it by washing in n- heptane. The task of monitoring the residual solvent is studied by wide-line 1 H NMR and ATR IR spectroscopy. In terms of methodology, the task is complicated by the accumulation of low molecular weight fragments of broken UHMWPE macromolecules, which are difficult to distinguish from short solvent molecules, in highly oriented fibers.