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In order to solve the problem of rail insulation failure caused by the iron scraps adsorbed on the wheel set falling into the rail gap when the train passing through the rail gap insulation causes vibrate,taking the silane-modified polyurethane pre-polymers as base gum and the gas phase method of white carbon black compound nanometer calcium carbonate as a reinforcing filler, by studying the base glue, packing, plasticizer, hydrocarbon remover, coupling agent and the dosage of catalyst on the properties of gel, gel formula was optimized and the preparation of a kind of fast curing silane-modified polyurethane pre-polymers insulating sealant. The best formula was: 100 parts silane-modified polyurethane pre-polymer, 200 parts nanometer calcium carbonate, 20 parts vapor phase silica, 60 parts PPG2000, 3 parts A-171, 3 parts A-1120, 1 part organo-tin catalyst, 1 part antioxidant, and 40 parts diluent. After testing, under 25 ℃, the surface dry time was 5 minutes, the tensile strength of the test piece was 2.6 MPa and the tensile expansion rate was 379%. The film was dense and uniform after gluing, with good thermal stability and weatherability, which metthe technical requirements of rail gap insulation repair. [ABSTRACT FROM AUTHOR]

In this paper, a kind of ultrasonic transmission composite material is studied. Epoxy resin is used as adhesive material, metal powder with small acoustic impedance is added to improve the ultrasonic conductive performance, liquid rubber CTBN is added to toughen and modify, mercaptan curing and fatty amine accelerator are added to shorten the curing time, and a kind of composite material with good adhesive viscosity, good toughness, short curing time and ultrasonic penetration is developed functional composite materials with strong overactivity. It provides a solution to the problem that the transmission channel of the real-time monitoring system of ultrasonic rail breaking is cut off and the monitoring function cannot be played. [ABSTRACT FROM AUTHOR]