Solid‐state shear pulverization of post‐industrial ultra‐high molecular weight polyethylene: Particle morphology and molecular structure modifications toward conventional mechanical recycling
Ultra-high molecular weight polyethylene (UHMWPE) is one of the most prominent high-performance thermoplastics for biomedical, leisure, and coating applications. Large-scale recycling of UHMWPE is extremely difficult due to the high melt viscosity of the material as well as its exceptional chemical resistance and impact strength. There is a need for a commercially scalable methodology that can process the waste feedstock for mechanical recycling while sustaining the outstanding physical properties of the material. Solid-state shear pulverization (SSSP) is a continuous, twin-screw extruder-based processing technique in which the low-temperature application of shear and compressive forces impart changes in structure at different length scales to overcome the challenges of difficult-to-recycle polymers. This paper investigates the use of SSSP in mechanically recycling post-industrial scrap UHMWPE (rUHMWPE) material from a local ski and snowboard manufacturer. The SSSP-processed particles are flat, micron-scale flakes with enhanced surface area, which can sinter very quickly when compression molded. The molded rUHMWPE samples in turn exhibit enhanced ductility and toughness compared to the as-received scrap material, based on the tunable mechanochemical modification of the ethylene chains.
Polymer Engineering & Science
Johnson, Riggs W.; Scopelliti, Haley R.; Herrold, Nathan T.; and Wakabayashi, Katsuyuki. "Solid‐state shear pulverization of post‐industrial ultra‐high molecular weight polyethylene: Particle morphology and molecular structure modifications toward conventional mechanical recycling." (2023) : 319-330.