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‖ NBR And HNBR Sealing

Sep 19, 2016

Nitrile rubber is made by emulsion polymerization of acrylonitrile and butadiene, acrylonitrile-butadiene rubber is mainly produced by emulsion polymerization at low temperature, excellent oil resistance, high wear resistance, heat resistance, strong adhesion. The drawback is the low temperature resistance, resistance to ozone is bad, poor insulation, slightly lower elasticity. Nitrile rubber is mainly used in the manufacture of oil-resistant rubber. Abbreviation NBR from copolymerization of butadiene and acrylonitrile, a synthetic rubber. Are resistant to oils (paraffin oil in particular), good aging resistance of synthetic rubber. NBR acrylonitrile content (%) include 42~46, 36~41, 31~35, 25~30, 18~24 and other five. Acrylonitrile content, the more the better oil resistance, cold resistance decreases. It can be 120 degrees in the air or in oil at 150 c for long-term use. In addition, it also has excellent water resistance, air tightness and excellent bonding properties. Widely used in a variety of oil-resistant rubber, various oil resistant gaskets, gasket, sleeve, flexible packaging, flexible hoses, printing and dyeing rollers, cables, plastic materials, in the automotive, aerospace, petroleum, photocopying and other industries becomes essential for elastic material.

NBR has excellent oil resistance. Copolymerization of butadiene monomer-Shun-, trans-and 1,2--fire three different types of chain structure. About trans-78% in the typical structure of NBR. As the NBR molecule chains containing cyano, oil (such as mineral oil, liquid fuel, vegetable oil and solvent resistance) than natural rubber, neoprene rubber and styrene-butadiene rubber. Compared with other rubber NBR has a wide service temperature, its long-term use temperature of 120C and NBR has good resistance to low temperature, low glass transition temperatures of up to -55C.

NBR resistant good chemical stability, good processability, with its production of nitrile content structure their relative density increases, the curing speed and tensile strength increases, but decreased elasticity, cold becomes worse. Because of NBR nitrile easy electric polarization, dielectric properties of down, is a semiconductor of rubber. NBR can ACN content height, divided into ultra high, high, medium high, medium and low acrylic nitrile 5. Production-continuous and batch polymerization method two. Continuous polymerization method is typically used to less variety and production quantity production, and low consumption. Batch polymerization method is suitable for variety and small batch production, accumulate check-use less construction consumption high. So far, see the trend of substitution.

Nitrile rubber with excellent physical and mechanical properties and processability, but long term acid gas and high temperature (150C) environmental performance than using fluoride gels and Acrylic adhesives, for which Germany companies, Canada Corporation and Japan has developed a high performance hydrogenated nitrile rubber (HNBR). In addition, developed a super cold and high purity acrylonitrile-butadiene rubber and the base of acrylonitrile-butadiene rubber (XNBR).