Abstract

Development of energy-efficient lubricants is a way to reduce energy consumption for transportation, with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils. Oligoether esters (OEEs), as a low-viscosity ester base oil, have characteristics such as simple synthesis and excellent lubrication effect, however, the application of OEEs in tribology field has rarely been investigated. The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure-property relationship (QSPR) through a combination of experiment and statistical modeling. Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption. Compared to branched-chain OEEs, straight-chain OEEs exhibited reduced wear, which was mainly due to the thicker adsorption film formed by the straight-chain structure. Furthermore, carbon films were detected on lightly worn surfaces, indicating that OEEs underwent oxidation during the friction process. Based on the results of principal component analysis (PCA) and partial least squares (PLS), it could be found that the predictive models of viscosity–temperature performance, thermal stability performance, coefficient of friction (COF), and wear volume (WV) performed well and robustly. Among them, COF and WV can be best predicted with an R² of about 0.90.

中文翻译：

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作为高效润滑油的低粘度低聚醚酯 (OEE)：深入了解其结构与润滑性关系

摘要

开发节能润滑油是减少运输能源消耗的一种方法，倾向于设计有利于降低合成油粘度的分子。低聚醚酯(OEEs)作为一种低粘度酯类基础油，具有合成简单、润滑效果优良等特点，但其在摩擦学领域的应用却鲜有研究。本研究的目的是研究结构对 OEE 润滑性能的影响，并通过实验和统计建模相结合，开发基于定量结构-性能关系 (QSPR) 的 OEE 预测模型。结果表明，乙二醇链对润滑有积极贡献，醚官能团增加了吸附位点。与支链OEE相比，直链OEE的磨损减少，这主要是由于直链结构形成的吸附膜更厚。此外，在轻微磨损的表面上检测到碳膜，表明 OEE 在摩擦过程中发生了氧化。根据主成分分析（PCA）和偏最小二乘法（PLS）的结果，可以发现粘温性能、热稳定性能、摩擦系数（COF）和磨损量（WV）的预测模型表现良好且稳健。其中，COF和WV的预测效果最好，R ²约为0.90。