Modeling of polymer lubricating additives by DNA structure and elucidation of the effect of molecular structure on frictional properties

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K14640
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 18040:Machine elements and tribology-related
• Research Institution: Tokyo University of Science (2021); Kyoto University (2020)
• Principal Investigator: Yamashita Naoki 東京理科大学, 理工学部機械工学科, 助教 (50847746)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: トライボロジー / 潤滑 / 添加剤 / DNA / 分子構造

Outline of Final Research Achievements

The effect of polymer structure on friction properties was evaluated to improve the performance of lubricating additives. DNA was used as a model for polymer additives since complex molecular structures can be easily fabricated.
DNA structures such as linear or branched chains were fabricated, and friction measurements were performed. The results showed that lower friction coefficient was obtained when using DNA structure with linear structure. On the other hand, small amount of wear was obtained when using DNA structure with branched chains. The DNA structures were fluorescently labelled and the amount of adsorption on the substrate was evaluated. The results showed that the more branched the structure, the lower the adsorption tended to be. These results suggested that the more branched chains, the more firmly they are adsorbed on the substrate, which improves wear resistance, whereas they may not contribute as much to friction reduction.

Free Research Field

トライボロジー，

Academic Significance and Societal Importance of the Research Achievements

近年，自動車の燃費向上のためにエンジンオイルの低粘度化が進んでいることに加え，環境負荷の観点から水潤滑の利用も注目されている．このような低粘度溶媒の潤滑下では摺動部材の直接接触が生じやすいため，高分子型の添加剤を加えることによって表面を保護するとともに粘度指数向上が図られている．本研究で得られた成果は，これまで評価対象とされてこなかった高分子添加剤分子の構造が及ぼす吸着挙動や摩擦特性への効果を解明するものであり，添加剤の開発や選定における包括的な理解につながるだけでなく，最終的には摩擦・摩耗の低減に有効な潤滑の最適化へとつながることが期待される．