First, natural rubber NR
Definition: (Natural Rubber) Made of rubber tree-collecting latex, a polymer of isoprene.
Advantages: good elasticity, acid and alkali resistance, good wear resistance, high elasticity, tear strength and elongation.
Disadvantages: not heat-resistant, oil-resistant (resistant to vegetable oil) easy to age in the air, sticky to heat, easy to swell and dissolve in mineral oil or gasoline, alkali-resistant but not strong acid.
Application: It is the raw material for making tapes, hoses and rubber shoes, and is suitable for the production of shock-absorbing parts, rubber tube products used in automotive brake oil pipes, ethanol and other liquids with hydroxide.
Second, styrene-butadiene rubber SBR
Definition: (Styrene Butadiene Copolymer) a copolymer of butadiene and styrene.
Advantages: low-cost non-oil resistant material, good water resistance, good elasticity under 70 hardness, poor compressibility at high hardness, better wear resistance and aging resistance.
Disadvantages: It is not recommended to use strong acids, ozone, oils, oil esters and fats and most of the hydrocarbons. The mechanical strength is weak and can be blended with natural rubber.
Application: Widely used in the rubber tube industry, tire industry, footwear industry, cloth industry and conveyor belt industry.
Third, ethylene propylene rubber EPDM
Definition: Ethylene propylene rubber is a copolymer of ethylene and propylene. Therefore, it is excellent in heat resistance, aging resistance, ozone resistance and stability, but it cannot be sulfur-added.
Advantages: The general use temperature is minus 50-150 °C. Excellent resistance to polar solvents such as alcohols and ketones: good weather resistance and ozone resistance, excellent water resistance and chemical resistance, alcohols and ketones, high temperature steam, gas With good impermeability.
Disadvantages: Not recommended for food use or exposure to aromatic hydrogen.
Application: Seals or parts for sanitary equipment in high temperature steam environment. Rubber parts in the brake (brake) system. Seal in the radiator (car tank).
Fourth, nitrile rubber NBR
Definition: (Nitrile Rubber) is a copolymer of acrylonitrile and butadiene.
Advantages: The content of acrylonitrile is from 18% to 50%. The higher the acrylonitrile content, the better the resistance to the fossil fuel hydrocarbon fuel oil, but the low temperature performance is worse. The general temperature range is minus 25-100 °C. Nitrile rubber is one of the most commonly used rubbers for oil seals and O-rings. It has good oil, water, solvent and high pressure resistant properties. Good compressibility, abrasion resistance and elongation.
Disadvantages: Not suitable for use in polar solvents such as ketones, ozone, nitrohydrocarbons, MEK and chloroform.
Application: It is used to make fuel tanks, lubricating oil tanks and rubber parts used in fluid media such as petroleum hydraulic oil, gasoline, water, silicone oil, diester lubricating oil, etc., especially sealing parts. It can be said that it is the most widely used and lowest cost rubber seal.
Five, neoprene CR
Definition: (Neoprene, Polychloroprene) is a polymerization of chlorobutene monomers.
Advantages: The rubber after vulcanization has good elastic wear resistance, is not afraid of direct sunlight, has good weather resistance, is not afraid of intense distortion, and is not afraid of refrigerant. It has good elasticity and good compression deformation. It has anti-animal and vegetable oil properties. It does not affect physical properties due to neutral chemicals, fats, oils, various oils and solvents. It has anti-burning properties.
Disadvantages: It is not recommended to use R12 refrigerant-resistant seals, rubber parts or seals on household appliances in chemicals such as strong acids, nitrohydrocarbons, esters, chloroforms and ketones.
Application: Suitable for making all kinds of parts that are in direct contact with the atmosphere, sunlight and ozone. Suitable for all kinds of flame-resistant and chemical-resistant rubber products, such as ozone-resistant rubber hoses, hydraulic hoses exposed to the air, etc.
