硫黄系潤滑油のトライボ化学安定性と分子構造の関係

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. In this study, the goal is to reduce wear and delay decomposition by using sulfur-based lubricants in which sulfur is introduced into the chemical structure of ADE. Using Q-mass, the tribochemical decomposition properties of ADE and sulfur-based lubricants were investigated. ADE decomposed at a sliding distance of 6 km, whereas mono alkyl phenoxathiin (MAPT) and di alkyl phenoxathiin (DAPT) were observed to decompose at a sliding distance of 30 km or more. APTs are thought to have exhibited a long induction period because they produce iron sulfide on sliding surfaces and acquire wear resistance. In addition, DAPT with more side chains showed better wear resistance. This is thought to be because the increase in side chains reduces the shear strength of the interface compared to MAPT.