2026-10-14T19:24:57Z https://www.scidb.cn/oai

10.57760/sciencedb.01240 2026-09-10T14:51:30Z

2026-09-10 Structure-Activity Relationship between Two Types of Synthetic Hydrocarbon Base Oils and the Adaptability of Lubricating Additive doi:10.57760/sciencedb.01240 en This study investigates two synthetic base oils—highly branched polyethylene (HBPE) and polyalphaolefin (PAO4) —through comprehensive structural and performance analyses. Their molecular architectures were characterized using gas chromatography (GC), infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). The thermal stability, oxidation resistance, and rheological behavior were evaluated via thermogravimetric analysis (TGA), pressurized differential scanning calorimetry (PDSC), and rheological measurements. Further investigation was conducted into the adaptability of the two with respect to the lubricant additive dibutyldithiocarbamate (DBDTC), including the effects of the additive on the physicochemical properties, oxidative stability, and tribological performance of the lubricating oil. Additionally, the wear scar morphology and element distribution were characterized using scanning electron microscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). Key findings reveal that HBPE exhibits higher branching density and isomerization than PAO4 but inferior thermal and oxidative stability. However, HBPE demonstrates superior tribological properties, including enhanced friction reduction, anti-wear performance, and extreme pressure resistance. Upon DBDTC addition, both lubricants showed improved thermal-oxidative stability and tribological behavior, with PAO4 displaying significantly greater responsiveness: a 38.93% reduction in friction coefficient, 78.15% lower wear rate, and a 163.16% increase in PB value, compared to 15.05%, 44.97%, and 70.88% improvements for HBPE, respectively. SEM-EDS analysis confirmed the formation of a sulfur- and carbon-rich tribofilm on worn surfaces, indicating that DBDTC's adsorption and tribochemical reactions generate a protective boundary layer. This film effectively minimizes direct asperity contact, thereby enhancing lubrication performance. The distinct response of PAO4 and HBPE to additive incorporation provides valuable insights for formulating high performance lubricants. highly branched polyethylene; poly α-olefin; dibutyldithiocarbamate; oxidation stability; extreme pressure and anti-wear; friction reduction performance Wang Mengxuan Li Ting Du Hengrui Hu Wenjing Han Sheng Li Jiusheng PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset http://www.doi.org/10.16078/j.tribology.2025186 Science Data Bank