Advanced Materials Research Vol. 177

Abstract: UV-curable waterborne polyurethane/acrylate (WPUA) composite resin was prepared, and its properties were compared with those of waterborne polyurethane resin. Results showed that the particle size distribution of the compounding resin was broader, and the compatibility of two phases in resin system became better after adding the acrylate into polyurethane. Moreover, water and alcohol resistances, and mechanical properties of composite resin were superior to those of waterborne polyurethane resin. Comprehensive properties of resin film were the best when photoinitiator amount is 3% of resin.

Abstract: The three-way catalyst with different cell shape substrates was prepared by the different washcoat loadings. Its catalyst’s light-off characteristics were investigated by the simulating calculation and the engine bench experiment. The experimental results showed that, heat transfer coefficient (Hs) couldn’t be improved by the increase of coating rate, in contrast heat transfer coefficient (Hs) and the catalytic conversion decreased when the coating rate was more than 45%. Therefore, it had some negative effects on the light-off characteristics and air-fuel ratio property. The calculation analyses and the engine bench experiment also proved that the best coating rate was 45% for the substrate of 400cpsi.

Abstract: To improve AO resistance of polyimide, a type of polyimide/silica (PI/SiO2) hybrid film was prepared by the sol-gel process. The coupling agent p-aminophenyltrimeth- oxysilane (APTMOS) was chosen to enhance the compatibility between the polyimide (PI) and silica (SiO2). AO resistance of the PI/SiO2 hybrid films were tested in the ground-based simulation AO facility. The erosion yield of the films was 4.7×10-26 cm3/atom, decreased by two orders of magnitude compared with the value of 3.0×10-24 cm3/atom of the polyimide film. Results from FTIR, XPS, AFM on AO treated polyimide/silica hybrid films indicate the formation of a passivating inorganic SiO2 layer. The layer significantly retards the penetration of oxygen atoms, preventing further degradation of the polymer in the bulk. The addition of SiO2 in polyimide does not significantly alter the optical properties of polyimide during AO exposure.

Abstract: Aiming at repairing aluminum alloy wear-out parts, the multiple compound metallic-membrane plating is researched with anodic oxidation, chemical plating Ni-P and later heat processing, blacken processing. Experiments show that this plating has many advances such as lower porosity, stronger binding force, higher hardness, better corrosion and abrasion resistant, another, this method of repairing only needs simple condition and is easy to be operated, this technology of repairing provides a new method for repairing of aluminum alloy wear-out parts.