アルキルフェノキサチインのトライボ化学分解に関する研究

抄録

It has been reported that alkyl diphenyl ether (ADE) exhibits excellent wear resistance and does not decompose unless nascent surface is exposed. However, under extreme contact conditions, decomposition of ADE was observed when the sliding surfaces wore down. This study aims to extend the period of nascent surface exposure by introducing sulfur into the chemical structure. Using Q-mass, the tribochemical decomposition properties of ADE and monoalkylphenoxathiin (MAPT) were investigated. While ADE began to decompose after a sliding distance of 10 km, MAPT did not show decomposition until approximately 30 km, indicating a threefold increase in induction period due to sulfur introduction. This result suggests that the formation of a tribofilm composed of iron sulfide, arising from the chemical reaction of sulfur at active sites, imparts superior wear resistance. Additionally, the gaseous hydrocarbon generation observed with ADE was not seen with MAPT. The likely cause is the high reactivity of sulfur, which leads to catalyst poisoning of the active sites on nascent surface, thereby inhibiting the tribochemical decomposition of the lubricant.