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This paper first describes the overview of the development of the PPTA fibers, reviewed the current status of research of the performance characteristics of the fiber surface modification, composite and applications. On this basis, the three aspects, a surface modification of the PPTA fibers were studied. Studied the effect of the surface of the PPTA fibers treated with phosphoric. Orthogonal design of experimental conditions, and the breaking strength of the monofilament, infrared spectroscopy, scanning electron microscopy, contact angle experiments were characterized by fiber strength, surface functional groups, microscopic surface morphology, invasive changes. The results show that the phosphate treatment increased the polarity of the surface of the fiber, improving the interface of the fiber and resin composite. The reaction mechanism speculated. By variance analysis of the experimental results found: Influence of temperature on the fiber wettability significant concentration and time has little effect on wettability; strength, concentration and time, a significant influence on the strength of the fiber, the temperature on the fiber strength The impact was not significant. Therefore, in order to obtain the best wettability and the best strength, and to establish the optimum modification conditions: with 5% phosphoric acid at 55 ℃ sonicated for 1h. First treated with phosphoric acid, and then further treated with a rare earth solution treatment effect of the surface of the fiber. The results show that, the further processing of the rare earth is almost no damage to the strength of the fiber. The wettability of the fiber after the processing has been further improved. In addition, from the view of the cleavage planes of the fiber and epoxy resin composite material, the sticky surface of the fiber after treatment more resin between the fibers and the resin interface, and there are a large number of filiform peeling, while the fibers themselves also occurs The microfibrillated axial splitting failure of treatment, the fibers and the resin to form a good interface. Testing of fiber and resin interfacial shear strength, shear strength with increasing rare earth concentration trend first increases and then decreases, the interfacial shear strength of the fiber after a 0.9% solution of rare earth processing maximum. Further, the PPTA pulp replacing asbestos reinforced matrix, a phenolic resin as the base system into rubbing composites. The results show that the PPTA pulp was obtained a composite material of the high temperature wear was significantly higher than that of asbestos. The high temperature wear resistance of the composite material obtained with the the PPTA pulp system after the phosphoric acid treatment, and phosphoric acid / rare earth integrated processing is further improved. Finally, a preliminary study on the impact strength of the obtained composite material.
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