Novel POSS based nanohybrids for improving tribological properties of liquid paraffin

Abstract

Polyhedral oligomeric silsesquioxane (POSS) based nanohybrids were prepared via “thiol–ene click” reaction between vinylPOSS and alkyl mercaptan. The structure and composition of these hybrids were characterized by ¹H nuclear magnetic resonance (¹H NMR), thermo-gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The effects of carbon chains of mercaptan and concentration variations of POSS nanohybrids on the tribological performance improvements of liquid paraffin (LP) were investigated. According to our experimental results, the optimal concentration of POSS nanohybrids in LP was 0.40 wt%, corresponding to the lowest friction coefficients of 0.099 (for OS-POSS additive) and 0.101 (for OD-POSS additive) respectively. POSS nanohybrids can achieve homogeneous dispersion in LP, while a hard, stable Si–O cage in their molecular structure provided effective wear resistance. These nanohybrids were expected to be useful for more lubricating oil systems, which possess great scientific values and promising application prospects compared with pure solid or liquid lubricating additives.