The effect of temperature and strain rate on the impact performance of recyclable all-polypropylene composites

Abstract

Highly oriented polypropylene (PP) tapes, with high tensile strength and stiffness achieved by molecular orientation during solid state drawing, are consolidated to create fully recyclable, high performance “all-polypropylene” (all-PP) composites. These composites possess a large processing temperature window (>30 °C) and a high volume fraction of highly oriented PP reinforcement phase (>90%). This large processing window is achieved by using co-extruded, highly drawn PP tapes. This paper investigates the relationship between the impact resistance of all-PP composite laminates based on these highly oriented co-extruded PP tapes, and the temperature and velocity of impact. Unlike isotropic PP, the highly oriented nature of all-PP composites means that a significant influence of glass transition temperature is not observed and so all-PP composites retain high impact energy absorption even at low temperatures. Finally, the ballistic impact resistance of all-PP composites is investigated and compared with current commercial anti-ballistic materials.