Comparative Study of Squalane Products as Sustainable Alternative to Polyalphaolefin: Oxidative Degradation Products and Impact on Physicochemical Properties

The growing demand for sustainable lubricant solutions is driving the exploration of biobased materials that can deliver comparable performance to conventional, primarily fossil-based lubricant chemistries. This study focuses on squalane as sustainable base oil, which can be derived from different renewable sources. A total of three squalane products were evaluated for ther-mal-oxidative stability and benchmarked against a polyalphaolefin PAO4 of the same total carbon number. Oil samples subjected to artificial alteration in a closed reactor underwent standard lub-ricant analyses, including infrared spectroscopy, to determine the conventional degradation changes over time. Additional in-depth information, by direct infusion high-resolution mass spec-trometry and gas chromatography coupled with triple quadrupole mass spectrometry were em-ployed to identify oxidation degradation products. The results revealed substantial variability in the stability of squalane products, suggesting that differences in raw materials and production processes have a profound influence on their performance, as well as rheological properties. Furthermore, detailed mass spectrometry analysis was applied to identify degradation products specific to poly-alphaolefin and squalane, respectively, and to understand their impact on the conventional phys-icochemical properties. While polyalphaolefin predominantly generated short-chain carboxylic acids as degradation products, squalane oxidation also produced several alcohols and ketones. Despite these differences, squalane demonstrates potential as a non-fossil hydrocarbon-based base oil, as squalane products matched and even outperformed stability of PAO4.