To reduce friction, especially under high-temperature conditions, an oil-soluble polymeric friction modifier (polymeric FM) with a methacrylate backbone and hydroxyl groups has been developed. It was designed to have high adsorption performance and to increase in size when dissolved in base oil as the temperature is increased. To investigate the temperature dependence of the structural and tribological characteristics of the adsorbed layer formed on a metal surface by the polymeric FM, neutron reflectometry measurements and nano-to-macro tribological tests were conducted. The measurements revealed that the polymeric FM adsorbed efficiently on a Cu surface and formed a 6.0-nm-thick adsorbed layer at 23 °C. This adsorbed layer was highly swollen, and its thickness became about three times larger at 100 °C. Nanoscale friction tests using an atomic force microscope showed that the swollen-state adsorbed polymeric FM layer exhibited low-friction and surface-protection performance at 100 °C. Macroscale friction tests revealed the tribological behaviour of an adsorbed polymeric FM layer in elastohydrodynamic lubrication and mixed lubrication regimes. At higher temperatures, the increase in shear resistance due to the effect of thin-film lubrication was suppressed by the weaker segment–segment interaction, causing the boundary contact of the adsorbed polymeric FM layer to have low frictional properties on both ball and disc surfaces. The low-friction mechanism of the adsorbed polymeric FM layer at higher temperatures was justified by associating the temperature with the layer thickness.

为了减少摩擦，特别是在高温条件下，已经开发了具有甲基丙烯酸酯主链和羟基的油溶性聚合物摩擦改性剂（聚合物FM）。它的设计具有很高的吸附性能，并随着温度的升高溶于基础油时尺寸会增大。为了研究通过聚合物FM在金属表面形成的吸附层的结构和摩擦学特性的温度依赖性，进行了中子反射测量和纳米至宏观的摩擦学测试。测量结果表明，聚合物FM在Cu表面有效吸附，并在23°C时形成6.0 nm厚的吸附层。该吸附层高度溶胀，并且其厚度在100℃下变为约三倍大。使用原子力显微镜的纳米级摩擦试验表明，溶胀态的吸附聚合物FM层在100°C时表现出低摩擦和表面保护性能。宏观摩擦试验表明，在弹性流体动力润滑和混合润滑方式下，吸附的聚合物FM层的摩擦学行为。在较高的温度下，由于薄层链节之间的相互作用而抑制了由于薄膜润滑作用引起的抗剪切力的增加，从而导致吸附的聚合物FM层的边界接触在球和圆盘表面上均具有低摩擦性能。通过将温度与层厚度相关联，可以证明在较高温度下吸附的聚合物FM层的低摩擦机理。