Fabrication of a polymer/aligned shish-kebab composite: microstructure and mechanical properties

Abstract

A shear-induced ultrahigh molecular weight polyethylene (UHMWPE) shish-kebab mat (USKM), in which shish-kebabs are well aligned, has been achieved from a dilute UHMWPE solution. Such a USKM is incorporated into linear low density polyethylene (LLDPE) as a reinforcement filler. Isothermal crystallization shows that the USKM acts as an effective nucleating agent for LLDPE crystallization, leading to enhanced crystallinity, long period, and lamellar thickness of the USKM/LLDPE composite. Instead of shish-kebabs, only aligned fibrils are observed in the composite. Such fibrils consist of a shish structure wrapped with LLDPE chains and good bonding at the interface between the fibril and matrix is achieved. Consequently, the interfacial adhesion is expected to improve and favorable stress transfer is realized. Together with good bonding, the superior strength of the shish structure and the above enhanced crystalline parameters contribute to a significant increment in the tensile strength and modulus of the composite, as compared to pure LLDPE.