Oil-Loaded Mesoporous Silica to Enhance the Lubrication of Polypropylene Resin Composite Materials

Abstract

Polymer self-lubricating materials have advantages such as low friction coefficient, good wear resistance, and high work efficiency, giving them wide application potential in friction and wear. This work fabricated polymer-based self-lubricating materials by incorporating oil-loaded mesoporous silica nanoparticles (MSNs + YR1800) in the polypropylene resin (PP). The effects of different content of MSNs + YR1800 on the tribological and mechanical properties of the obtained self-lubricating composite materials were studied. The results indicate that the content of MSNs + YR1800 in composite materials significantly impacts their tribological properties. When the content of MSNs + YR1800 was 10 wt%, the coefficient of friction reduced to 0.09,which was 84.5% lower than for PP and 78.6% lower than for composite materials containing 5 wt% mesoporous silica nanoparticle (MSNs). Compared with pure PP, the wear rate decreases from 4.93 × 10−11 m3∙Nm−1 to 4.43 × 10−13 m3∙Nm−1, which is reduced by two orders of magnitude. The excellent tribological properties of composite materials are attributed to the high specific surface area, large pore volume, strong adsorption capacity, and high oil loading capacity of mesoporous silica nanoparticle as nanofillers. The MSNs + YR1800 release lubricants to form a lubricating oil film during the friction process under load conditions, preventing direct contact between the friction pair and the surface of the composite material. Compared with polymer-silica hybrid oil-loaded microcapsules, MSNs + YR1800 can effectively reduce lubricant leakage, prolong operation life, improve lubrication efficiency, and ensure the continuous and stable existence of lubricating oil films.