??Nitrile rubber seals heat resistance

??Nitrile rubber (NBR) structure due to the presence of polar cyano, therefore high stability of non-polar or weakly polar mineral oil, animal and vegetable oils, liquid fuels and solvents, and aromatic solvents, ketones , esters and other polar substances is because they have swelling effect. Nitrile rubber in the nature of the solvent, the swelling solvent is related to the lower aniline point of the solvent or higher aromatic content, the greater the swelling capacity, and nitrile rubber poorer stability in a solvent. NBR easily due to the presence of an electric field polarization of cyano, thereby reducing the dielectric properties. Nitrile rubber is a semiconductor rubber, which combine higher amount of acrylonitrile, dielectric properties worse.

??NBR heat resistance than natural rubber, styrene-butadiene rubber and neoprene. Compared with other rubber, nitrile rubber has a wide temperature range, long-term use at 120 ? in air heavy, if isolated from the air, can be long-term use at 160 ?. NBR heat resistance and therewith increase the amount of bound acrylonitrile.

??Nitrile rubber seals four main drawback strong oxidant properties and resistance to ozone resistance poor, in order to allow the nitrile rubber used in some industries, it is often added antiozonants polyamine p-phenylenediamine and paraffin and antioxidants, polyols phenol and organic phosphite.