Processing and Properties of Melt Processable UHMW-PE Based Fibers Using Low Molecular Weight Linear Polyethylene's

Abstract

The rheology, solid state drawability, morphology, and mechanical properties of polyethylene blends containing ultrahigh molecular weight polyethylene (UHMW-PE) and linear-low molecular weight polyethylene waxes (PEwax) are explored. Addition of PEwax enables melt processing of UHMW-PE and improves solid state drawability, providing opportunities in recycling of UHMW-PE waste. Small angle X-ray scattering results show that both PEwax and UHMW-PE align fully in the drawing direction, irrespective whether the PEwax has an Mn below or above the critical molecular weight at which entanglements can form (Mc). Tensile moduli of drawn specimen are in accordance to the Irvine–Smith model confirming that both UHMW-PE and PEwax align in the drawing direction and no chain slip occurs toward zero strain and both UHMW-PE and PEwax fractions, irrespective of their molecular weight, contribute fully to the modulus. Tensile strength of the blends scales according to the rule of mixtures where PEwax below Mc scale toward zero and those above Mc do contribute to the tensile strength. Modulus hence can be regarded as insensitive to the molecular weight of the PEwax used, whereas strength does show to be sensitive to the molecular weight of the PEwax.