Design of Modified Silicone Oils for Advanced Heat-Resistant and Wear-Resistant Grease Lubricants

Grease lubricants used under high-temperature and high-load conditions require base oils with excellent thermal stability, low friction, and strong surface protection. Perfluoropolyether (PFPE)-based oils have been widely used for such applications because of their outstanding chemical and thermal resistance; however, increasing PFAS-related concerns have created a need for non-fluorinated alternatives. Silicone oils are promising candidates owing to their flexible Si–O–Si backbone and inherent thermal stability, but their weak affinity toward metal surfaces often results in insufficient boundary lubrication and poor wear resistance.In In this study, functional silicone oils were designed through the molecular modification of polymethylhydrosiloxane (PMHS). By introducing selected functional organic moieties into the silicone structure, the modified oils were tailored to improve compatibility with grease formulations, affinity toward metal surfaces, and tribological durability under high-temperature conditions. The resulting silicone-based oils are expected to enhance friction and wear performance in grease lubricants, suggesting their potential as PFAS-free base oils for thermally stable and wear-resistant lubrication systems.