Influence of Thermal Aging on the Sliding Wear of a Biocomposite Material Reinforced with Bamboo Fibers

This study evaluated the effect of thermal aging on the tribological properties of biocomposites formed by an isotactic polypropylene matrix (iPP) reinforced with 20 wt% (PP/20F), 30 wt% (PP/30F), and 40 wt% (PP/40F) of randomly oriented bamboo fibers. iPP, along with the grafting of maleic anhydride molecules (MAPP), was used as a coupling agent. The accelerated thermal aging involved the continuous heating of the materials at 98 °C for 10 days. Wear tests were performed under the Pin-on-Disk configuration to determine the wear factor (K) and the friction coefficient (µ) of the materials. After thermal aging, the µ value of the PP/20F composite increased by 40.5%, while, for raw PP, PP/30F, and PP/40F, the increase was 2.1, 7.5, and 2.2%, respectively. The aged PP/30F composite achieved the highest µ value. The loss of wear resistance due to aging was more prominent in the raw PP. The K factor of the aged and unaged PP/20F was the lowest. The use of scanning electron microscopy allowed identifying that adhesive, abrasive, and fatigue wear mechanisms were the dominant ones.