Microstructural origin of physical and mechanical properties of ultra high molecular weight polyethylene processed by high velocity compaction

Ultra High Molecular Weight Polyethylene (UHMWPE) is a semi-crystalline polymer with exceptional wear and impact properties, but also a very high melt viscosity, owing to its extremely long chains. Therefore, UHMWPE is non-melt processable and its processing is long and expensive. However, a new process, High Velocity Compaction (HVC), allows processing UHMWPE within short processing times via sintering. Several high velocity impacts are applied to a powder-filled die to provide self-heating. The sintering is then obtained by local fusion/recrystallization. In this study, the physical and mechanical properties of UHMWPE processed by HVC are investigated. Ductile UHMWPE with a high modulus was obtained. The particular microstructure of the material resulting from the sintering by fusion/recrystallization has then been characterized. It appears that mechanical properties of HVC-UHMWPE are governed by the microstructure induced by processing conditions, and hence can be adjusted for a given application.