Study On The Tribological Properties Of Engineering Plastics In Hydrogen Peroxide

As a typical kind of dynamic seal material, engineering plastics have been widely used in the engineering machinery. On the background of dynamic seal material used in hydrogen peroxide (H2O2), the tribological properties of ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE) and copolyoxymethylene (POM) in high concentrations of hydrogen peroxide solution were discussed. By virtue of surface topography, surface spectroscopy, infrared spectroscopy and other means, the influence of stronger oxidation of H2O2 on the physical and chemical characteristics of these materials, the wear and failure mechanism of them in high concentrations of H2O2 were made a in-depth study. A preliminary theoretical and experimental basis for the selection and the design of the sliding bearing materials under strong oxidizing environment of H2O2 were provided. The main contents of this paper are as follows:1. Friction and wear properties of UHMWPE, PTFE and POM in H2O2 were studied. By changing concentrations of hydrogen peroxide, load and sliding velocity, the results showed that the tribological properties of UHMWPE was significantly better than that of PTFE and POM.2. The wear mechanism of UHMWPE, PTFE and POM in H2O2 was preliminary established. The wear mechanism of UHMWPE was a mixture of slight abrasive wear, a small amount of plastic deformation wear and oxidation wear. The wear mechanism of PTFE was a mixture of severe abrasive wear and plastic deformation wear. The wear mechanism of POM was oxidation and corrosive wear.3. In hydrogen peroxide, the chemical groups and oxidation index variation of UHMWPE, PTFE and POM before and after test were analyzed deeply by transmission infrared spectroscopy. Friction and wear mechanism of these engineering plastics in H2O2 were considered in perspective of tribo-chemistry.The main innovations of this dissertation are as follows. The tribological properties of three engineering plastics were systemically studied in the condition of H2O2 which has strong oxidation. The friction and wear mechanism of these engineering plastics under strong oxidant were firstly studied by analysizing of worn samples in the tribo-chemistry perspective combined with technology of transmission infrared spectroscopy.