Natural rubber NR
Natural Rubber is a polymer of isoprene, which is made from rubber latex collected from rubber trees. It has good wear resistance, high elasticity, breaking strength and elongation. It is easy to age in the air and become sticky when exposed to heat, and it is in mineral oil or gasoline
Easy to expand and dissolve, alkali resistant but not strong acid resistant. Advantages: good elasticity, acid and alkali resistance 。 Disadvantages Weatherproof and oil resistant (vegetable oil resistant) It is the raw material for making adhesive tape, rubber hose and rubber shoes, and is suitable for making shock absorbing parts and products used in automobile brake oil, ethanol and other liquids with hydroxyl radicals.
SBR
(Styrene Butadiene Copolymer) The copolymer of butadiene and styrene, compared with natural rubber, has uniform quality, less foreign matter, better wear resistance and aging property, but weak mechanical strength, and can be mixed with natural rubber. Advantages: low cost non oil resistant material, good water resistance, good elasticity with hardness below 70, and poor compressibility with high hardness. Disadvantages: It is not recommended to use strong acids, ozone, oils, oil esters, fats and most hydrocarbons. It is widely used in tire industry, shoe industry, cloth industry and conveyor belt industry.
Butyl rubber IIR
Butyl Rubber is polymerized by isobutene and a small amount of isoprene. Because the movement of methyl steric barrier molecule is less than that of other polymers, the gas permeability is less, the resistance to heat, sunlight and ozone is greater, and the electrical insulation is better; yes
The polar solvent has high resistance, and the general use temperature range is - 54-110 ℃. Advantages: It is impermeable to most general gases, has good resistance to sunlight and odor, and can be exposed to animal or vegetable oils or vaporizable chemicals. Disadvantages: It is not recommended to use together with petroleum solvent, rubber kerosene and aromatic hydrogen. Used for inner tube, leather bag, rubber paste paper, window frame rubber, steam hose, heat-resistant conveyor belt, etc. of automobile tires.
Hydrogenated nitrile rubber HNBR
(Hydrogenate Nitrile) hydrogenated nitrile rubber is a kind of nitrile rubber in which some double chains are removed after hydrogenation. After hydrogenation, its temperature resistance and weather resistance are much better than ordinary nitrile rubber, and its oil resistance is similar to ordinary nitrile rubber. The general operating temperature range is - 25-150 ℃. Advantages: It has better abrasion resistance than nitrile rubber, and has excellent corrosion resistance, tensile resistance, tear resistance and compression properties. It has good resistance under atmospheric conditions such as ozone, and is generally used in detergents for washing clothes or dishes. Disadvantages: It is not recommended to be used in the hollow refrigeration industry of alcohols, esters or aromatic solutions, but widely used in environmental friendly refrigerants and R134a systems Sealing element Automobile engine system seal.
EPDM
(Ethylene propylene rubber) is made by copolymerization of ethylene and propylene, so its heat resistance, aging resistance, ozone resistance and stability are excellent, but sulfur addition is not allowed. To solve this problem, a small amount of the third component with double chains is introduced into the main chain of EP, which can be made into EPDM by adding sulfur. The general use temperature is - 50-150 ℃. Excellent resistance to polar solvents such as alcohol and ketone. Advantages: good weather resistance and ozone resistance, excellent water resistance and chemical resistance, alcohol and ketone can be used, high temperature steam resistance, and good gas impermeability. Disadvantages: Not recommended for food use or exposure to aromatic hydrogen. Seals for high temperature steam environment Seals or parts of sanitary equipment. Rubber parts in the brake (braking) system. Seal in radiator (car water tank).
NBR
(Nickel Rubber) is copolymerized by acrylonitrile and butadiene. The acrylonitrile content is 18% - 50%. The higher the acrylonitrile content, the better the resistance to petrochemical oil hydrocarbon fuel oil, but the low temperature performance becomes worse. The general use temperature range
- 25~100 ℃. Acrylonitrile butadiene rubber is one of the most commonly used rubber for oil seal and O-ring at present. Advantages: It has good characteristics of oil resistance, water resistance, solvent resistance and high pressure oil resistance. It has good compressibility, abrasion resistance and elongation. Disadvantages: Not suitable for polar solvents, such as ketones, ozone, nitrohydrocarbons, MEK and chloroform. It is used to make rubber parts, especially sealing parts, for fuel tank, lubricating oil tank and fluid media such as petroleum hydraulic oil, gasoline, water, silicone oil, diester lubricating oil, etc. It can be said that it is the most widely used rubber seal with the lowest cost at present.
Neoprene CR
(Neoprene, Polychloroprene) is polymerized from chloroprene monomer. Vulcanized rubber has good elasticity and wear resistance, is not afraid of direct sunlight, has excellent weather resistance, is not afraid of intense distortion, is not afraid of refrigerant, and is thin resistant
Acid and silicon ester resistant lubricating oil, but not phosphate ester hydraulic oil. It is easy to crystallize and harden at low temperature, and has poor storage stability. It has a large expansion amount in mineral oil with low aniline point, and the general use temperature range is - 50~150 ℃. Advantages: It has good elasticity and good compression deformation. The formula does not contain sulfur, so it is very easy to make. It has the characteristics of anti animal and vegetable oil. It will not affect the physical properties due to neutral chemicals, fats, grease, a variety of oil products, and solvents. It has flame retardant properties. Disadvantages: It is not recommended to use R12 refrigerant resistant seals among strong acids, nitrohydrocarbons, esters, chloroform and ketones, and rubber parts or seals on household appliances. It is suitable for making various parts that directly contact with the atmosphere, sunlight and ozone. It is suitable for all kinds of fire and chemical resistant rubber products.
Composition of synthetic rubber
Synthetic rubber is a polymer polymerized from oil and natural gas with dienes and alkenes as monomers. The polymer of rubber has broken through the process of monomer polymerization. At present, the world's leading rubber factories have begun to use the rubber with higher strength, which is assembled by ultrahigh polymers, and the cost is quite low.