Group IV Base Stock:

Abstract

Most of the industries are switching to synthetic lubricants owing to their better lubrication properties than conventional base oils. Among the synthetic base oil, polyalphaolefins (PAOs) have gained more attention because of their intrinsic attributes such as high viscosity indices, wide operating temperature range, better oxidation and thermal stability, lower volatility, biodegradability and low viscosity. According to consumer reports, PAOs are becoming the new standard as a lubricant, approximately 70% of new vehicles in 2019, having either PAO or PAO-based blended oils. PAOs are saturated synthetic hydrocarbons that are derived through the catalytic oligomerization of linear-α-olefin, i.e. 1-alkene. PAOs are designated in group IV by the American Petroleum Institute (API) and classified based on their kinematic viscosity at 100°C. Nowadays, PAOs are extensively employed as a high-performance base oil in many applications such as automatic transmission oil, hydraulic oil, automobile industry as engine lubricants and gear oil, turbine oil, compressor and pump oil and greases. It was also reported that the inclusion of a little proportion of nanoadditives in the base oils could improve several characteristics of the lubricating oils such as friction, wear resistance, load carrying capacity and thermal and rheological properties. Therefore, over the last few years, many researchers have investigated the various nanoparticles as an additive in the different grades of PAOs. This chapter discusses chemistry, synthesis processes, properties, advantages and tribological applications of PAOs. Besides, this chapter also elucidates the role of nanoadditive to assess the tribological performance of PAO-based nanolubricants.