Realizing mechanically reinforced all-polyethylene material by dispersing UHMWPE via high-speed shear extrusion

Abstract

Due to its extraordinary molecular weight feature (Mw > 106 g/mol), ultra high molecular weight polyethylene (UHMWPE) plays as an appropriate reinforcement for polyethylene. However, ultrahigh molecular weight also causes remarkably high melt viscosity, which hinders the solvent-free processing of UHMWPE. Here, we report a self-reinforcement all-polyethylene material, high density polyethylene (HDPE)/UHMWPE via a melt processing of high-speed shear extrusion. A critical reinforced content of UHMWPE, 0.1 wt%, has been discovered. After reaching such content, the tensile strength and Young's modulus of HDPE can be reinforced remarkably at 500 rpm. Thanks to the high shear, UHMWPE is uniformly dispersed and to form reinforcement network in the HDPE matrix. Interestingly, UHMWPE long chains enable the appearance of lamellae orientation and shish-kebab crystalline morphology in the injection molded parts, which are responsible for the mechanical reinforcement behavior observed. Our current work offers a convenient, solvent-free processing strategy to manufacture super polyolefin blends containing UHMWPE.