NR Natural Rubber
Natural Rubber is a polymer of isoprene, made from latex collected from rubber trees. It has good wear resistance, high elasticity, breaking strength and elongation. It is easy to ageing in air, viscous in heat, easy to expand and dissolve in mineral oil or gasoline, alkali-resistant but not strong acid-resistant. Advantages: good elasticity, acid and alkali resistance. Disadvantages: Weather-resistant, oil-resistant (vegetable oil) is the raw material for making rubber tape, hose, rubber shoes, and is suitable for making shock absorber parts, products used in automobile brake oil, ethanol and other liquids with hydroxyl radicals.
Styrene Butadiene Copolymer is a copolymer of butadiene and styrene. Compared with natural rubber, the copolymer has uniform quality, fewer foreign bodies, better wear resistance and aging resistance, but its mechanical strength is weak and can be mixed with natural rubber. Advantages: Low-cost non-oil-resistant materials, good water resistance, good elasticity under 70 hardness, poor compressibility at high hardness. Disadvantages: strong acids, ozone, oils, esters, fats and most hydrocarbons are not recommended. It is widely used in tire industry, footwear industry, cloth industry and conveyor belt industry.
Butyl Rubber is a polymer of isobutene and a small amount of isoprene. Because the movement of stereo barrier molecule of methyl is less than that of other polymers, it has less gas permeability, greater resistance to heat, sunlight and ozone, and better electrical insulation. It has great resistance to polar capacitors, and its temperature range is - 54 - 110 C. Advantages: It is impermeable to most general gases, and has good resistance to sunlight and odor. It can be exposed to animal or vegetable oils or gasifiable chemicals. Disadvantages: It is not recommended to use inner tube, leather bag, rubber paste paper, window frame rubber, steam hose, heat-resistant conveyor belt with petroleum solvent, kerosene and aromatic hydrogen.
NBR is a kind of NBR which removes part of double chains after hydrogenation. After hydrogenation, its temperature resistance and weatherability are much higher than those of ordinary NBR, and its oil resistance is similar to that of ordinary NBR. Generally, the temperature range is - 25 ~ 150 C. Advantages: Compared with NBR, NBR has better abrasion resistance, excellent corrosion resistance, tension resistance, tear resistance and compression properties.
Ozone and other atmospheric conditions have good resistance, generally suitable for laundry or dishwashing detergents. Disadvantage: It is not recommended to be used in the air conditioning and refrigeration industry in alcohols, esters or aromatic solutions. It is widely used in the sealing parts of environmental refrigerant R134a system. Seals for automotive engine system.
Ethylene propylene Rubber (EPDM) is a copolymerization of ethylene and propylene, so its heat resistance, aging resistance, ozone resistance and stability are excellent, but sulfur can not be added. In order to solve this problem, a small amount of the third component with double chains is introduced into the EP main chain, and EPDM can be made by adding sulfur. Usually, the temperature is - 50 - 150 C. Excellent resistance to polar solvents such as alcohol and ketone: good weather resistance and ozone resistance, excellent water resistance and chemical resistance, alcohol and ketone can be used, high temperature vapor resistance, good gas impermeability. Disadvantage: Not recommended for food use or exposure to aromatic hydrogen. Seals for high temperature water vapor environment. Seals or parts for bathroom equipment. Rubber parts in brake system. Seals in radiators (automobile water tanks).
Nitrile Rubber is synthesized by the copolymerization of acrylonitrile and butadiene. The acrylonitrile content ranges from 18% to 50%. The higher the acrylonitrile content, the better the resistance to petrochemical hydrocarbon fuel oil, but the lower the low temperature performance. Generally, the temperature range is - 25 ~ 100 C. Butadiene rubber is one of the most commonly used rubber for oil seal and O-ring at present. It has good properties of oil resistance, water resistance, solvent resistance and high pressure oil resistance. has good compressibility, wear resistance and elongation.
Disadvantage: Not suitable for polar solvents, such as ketones, ozone, nitrohydrocarbons, MEK and chloroform. It is used for making fuel tank, Lubricating Tank and rubber parts, especially sealing parts, used in fluid media such as hydraulic oil, gasoline, water, silicone oil and diester lubricating oil of petroleum system. It can be said that rubber seals are the most widely used and the lowest cost at present.
Neoprene and Polychloroprene are synthesized by the polymerization of chloroprene monomers. The vulcanized rubber has good elasticity, wear resistance, no fear of direct sunlight, excellent weather resistance, no fear of intense distortion, no fear of refrigerants, dilute acid, silicone ester lubricant, but not phosphate ester hydraulic oil. It is easy to crystallize and harden at low temperature, and has poor storage stability. It has large expansion in mineral oil with low aniline point. Generally, the temperature range is - 50 ~ 150 C. Advantages: Good elasticity and good compression deformation, the formula does not contain sulfur, so it is very easy to make. With anti-animal and vegetable oil properties, not because of neutral chemicals, fats, oils, a variety of oils, solvents and affect physical properties, with flame-retardant properties.
Disadvantage: It is not recommended to use sealing parts resistant to R12 refrigerant in strong acids, nitrohydrocarbons, esters, chloroform and ketones, rubber parts or seals on household appliances. Suitable for making all kinds of parts which are directly in contact with the atmosphere, sunlight and ozone. It is suitable for all kinds of fire-resistant and chemical-resistant rubber products.