The main-chain thermotropic liquid crystalline polymer (LCP) has been reported to be able to simultaneously lower friction coefficient and wear rate when introduced into poly (vinylidene fluoride) (PVDF) as the lubricant. In this investigation, we aim to obtain some insight into the lubricating mechanism of LCP. Through atomic force microscopy (AFM) and Raman spectroscopy, friction-induced in-situ nanocoatings of LCP are observed on friction PVDF domains, which arises from increasing surface temperatures and high shear thinning properties of LCP. Consequently, LCP nanocoatings obviously enhance microscopic hardness of friction PVDF domains. In other words, LCP nanocoatings could be treated as a type of protective lubricant to prevent the direct contact between counterface and PVDF domains, promote wear resistance and lower friction coefficient. To our best knowledge, such an interesting lubricating mechanism is rarely reported. Overall, this investigation not only proposes the novel lubricating mechanism of LCP, but also provides support for further tribological applications in the polymeric systems.

据报道，主链热致液晶聚合物（LCP）在引入聚偏二氟乙烯（PVDF）作为润滑剂时，能够同时降低摩擦系数和磨损率。在此调查中，我们旨在了解LCP的润滑机理。通过原子力显微镜（AFM）和拉曼光谱，原位摩擦诱导在摩擦PVDF域上观察到LCP的纳米涂层，这是由于LCP的表面温度升高和高剪切稀化特性引起的。因此，LCP纳米涂层明显提高了摩擦PVDF域的显微硬度。换句话说，LCP纳米涂层可被视为一种保护性润滑剂，以防止对接面和PVDF域之间直接接触，提高耐磨性并降低摩擦系数。据我们所知，很少有这样有趣的润滑机理报道。总体而言，这项研究不仅提出了LCP的新型润滑机理，而且还为聚合物体系中的进一步摩擦学应用提供了支持。