Enhanced tribological and corrosion resistance of PMMA-based composite coatings reinforced with SiO2, CNC, and lignin: Towards durable biomedical materials

This study investigates the development of silica (SiO 2 ), cellulose nanocrystals (CNC), lignin, and polymethyl methacrylate (PMMA) composites to enhance wear and corrosion resistance for joint implants. The lignin and SiO 2 fillers were grafted with polymer molecular chains, forming a network structure that effectively blocks corrosion pathways and reduces interchain spacing. CNC was added to further improve mechanical properties and act as lubricating additives. The resulting composite films demonstrated a 242% decrease in wear rate and a 135% reduction in the coefficient of friction with the addition of 0.01 wt% CNC. Corrosion resistance was significantly enhanced, with a 99.7% reduction in corrosion current density (I corr ) to 1.38 × 10 −10 A/cm 2 and a 1.145 V increase in corrosion potential (E corr ) at an optimal CNC filler ratio. This research presents a promising approach to enhancing the longevity and performance of biomedical materials.