The effect of the heat used during composite processing on the mechanical properties of fibrous reinforcement of polypropylene-based single-polymer composites.

In this study, we investigated the effect of heat treatment on the mechanical properties of high-tenacity polypropylene (PP) fibers. An application field of versatile polypropylene as fibers and tapes is the reinforcement of single-polymer composites. During consolidation at an elevated temperature, typically near the melt temperature of PP, the heat causes molecular relaxation of the strongly oriented molecular chains, which impairs mechanical properties.