Study on Synthesis and Lubricating Performance of Carbon Nanotubes-Poly (ethyl acrylate) Compound Emulsion as Additive in Water-Based Fluid

Carbon nanotubes-poly(ethyl acrylate) (coded as CNTs-PEA) compound emulsion was prepared making use of emulsion polymerization. The stability of the resulting CNTs-PEA compound emulsion was examined, while its micro-morphology was observed on a transmission electron microscope. Moreover, the effect of the CNTs-PEA compound emulsion as an additive on the friction-reducing, antiwear, and extreme-pressure properties of a water-based fluid was investigated on a four-ball machine and an MM-200 test rig, and the worn steel ball surfaces lubricated with different mediums were observed on a scanning electron microscope. It was found that the CNTs-PEA compound emulsion had good stability in atmosphere, which was attributed to its specific microstructure characterized by physical covering and chemical bonding between the CNTs and the polymeric molecular chains. The CNTs-PEA compound emulsion as the additive contributed to significantly improve the tribological behavior of the base fluid, which was related to the excellent mechanic properties of the CNTs and to the hard CNTs core-flexible PEA covering layer structure that was capable of reducing friction and wear by way of "rolling bearing effect".