Tribological Behavior of Polymer-Based Supramolecular Gel PUMA-PSMA During Lubrication State Transitions

Friction and wear are major contributors to energy loss and mechanical component failure, accounting for significant economic and environmental costs in industrial systems. This study introduced a novel supramolecular polymer gelator (PUMA-PSMA), synthesized via free radical polymerization and dissolved in 500SN base oil to form a high-performance PUMA-PSMA polymer gel lubricant. The gel demonstrated remarkable thermal stability, with initial decomposition temperatures increasing from 227.24 ℃ (3%) to 273.7 ℃ (6%), indicating enhanced structural integrity at elevated temperatures. Its thixotropic and shear-thinning properties ensured excellent creep recovery, which was essential for preventing lubricant loss and maintaining sealing performance under varying operating conditions.The tribological performance of the PUMA-PSMA gel was systematically evaluated using an MTM-2 micro-traction test machine under varying concentrations, loads, slip-roll ratios (SRR), and temperatures. Experimental results showed that the gel significantly reduced the friction coefficient compared to 500SN base oil and Grease-N. At a load of 40 N and 15% SRR, the average friction coefficient for PUMA-PSMA gel was 0.062 3, significantly lower than 0.065 5 for 500SN and 0.092 for Grease-N. Furthermore, the gel exhibited stable lubrication performance across a wide range of operating conditions, maintaining its structural and functional properties even under high speed and high SRR conditions. Statistical analysis (ANOVA) confirmed that concentration, load, and SRR have a highly significant effect on friction coefficient (pAdditionally, surface analysis revealed that the gel formed protective tribo-films composed of iron oxides and nitrides under extreme conditions, which contributed to its enhanced wear resistance. These properties made the PUMA-PSMA gel an ideal candidate for high-performance lubrication in industrial applications requiring robust thermal stability, low friction, and effective wear protection. In summary, the PUMA-PSMA polymer gel lubricant offerd significant advancements in reducing friction and wear across various operating conditions. Its ability to maintain a stable lubricating film, adapt to extreme mechanical and thermal environments, and provide reliable performance underscores its potential as a next-generation lubricant for demanding industrial environments.