Natural Rubber (NR)
Natural Rubber is made of Rubber latex which collected from Rubber trees, it is a polymer of isoprene with good wear resistance, high elasticity, tensile strength and elongation. It is easy to aging in the air, and become sticky under heating, also easy to expand and dissolve in mineral oil or gasoline. It has good alkali resistance but weaker in strong acid.
Advantages: good elasticity, acid and alkali resistance.
Disadvantages: weather resistance, oil resistance (can be resistant to vegetable oil)
Application: The raw material of tape, rubber hose, rubber shoes, and suitable for the production of shock parts, automotive brake oil, ethanol and other liquid with hydroxide used rubber products.
Styrene Butadiene Rubber (SBR)
Compared with natural rubber, SBR has better uniform quality, less foreign body, and better wear resistance and aging resistance, but the mechanical strength is weaker, it can be used by mixing with natural rubber.
Advantages: SBR has good heat resistance, wear resistance, aging resistance. It has good storage stability, and can be soluble in benzene, toluene, xylene, ethyl acetate, chloroform and other solvents. It’s a non-oil resistant material with low cost, good water resistance, hardness below 70 degree with good elasticity, but poor compressibility when high hardness.
Disadvantages: Do not recommended to use in strong acids, ozone, oils, esters of oils and fats and most hydrocarbons.
Application: It is widely used in tire industry, shoe industry, cloth industry and conveyor belt industry.
Butyl Rubber (IIR)
Butyl Rubber is formed by the polymerization of isobutylene with small amount of isoprene. Because the movement of methyl groups is less than other polymers, it has less gas transmittance, greater resistance to heat, sunlight and ozone, and better electrical insulation. Good resistance to polar capacitive agent, the general using temperature range is -54 ~110 degree.
Advantages: impermeable to most of gases, good resistance to sunlight and odor. It can be exposed to animals or vegetable oils and gasifiable chemicals.
Disadvantages: it is not recommended to together use with petroleum solvent, rubber kerosene and aromatic hydrogen the inner tube, leather bag, rubber paste paper, window frame rubber, steam hose, heat-resistant conveyor belt and so on.
Neoprene, Polychloroprene is composed of chloroprene monomer polymerization. After vulcanization, it has good rubber elasticity and abrasion resistance. It is anti-insolation and has good weather resistance, resistant to violent distortion, refrigerants, dilute acid, silicon ester lubricant, but not resistant to phosphate series of hydraulic oil. It is easy to crystallize and harden at low temperature, weak storage stability, and big expansion in low aniline point of mineral oil. In using temperature range is - 50 ~ 150 degree.
Advantages: good elasticity and good compression deformation, the formula contains no sulfur, so it is very easy to operate. It has anti-animal and vegetable oil properties, will not be affected by neutral chemicals, fats, oils, a variety of oils, solvents, and also has anti-fire properties.
Disadvantages: do not recommend to use in strong acids, nitrohydrocarbons, esters, chloroform and ketone chemicals.
Application: Rubber parts or sealing parts with R12 refrigerant, household appliances. Suitable for rubber products which direct contact with the atmosphere, sunlight, ozone parts, resist fire and chemical corrosion.
Ethylene propylene Rubber (EPDM)
Ethylene propylene Rubber is composed of Ethylene and propylene copolymerization, so it has good heat resistance, aging resistance, ozone resistance and stability, but weak in sulfuring. In order to solve this problem, in the main chain of the EP, importing sulfur after importing a double strand of the third component to be EPDM. Generally using temperature is - 50 ~ 150 degree. It has excellent resistance to the polarity solvent such as alcohol, ketone .
Advantages: good weather resistance, high temperature steam resistance, and ozone resistance, with excellent water resistance and chemical resistance, it can be used in alcohols and ketones, good permeability in gas.
Disadvantages: do not recommended for food use or exposure to aromatic hydrogen. Application: Sealing parts or parts of sanitary equipment in high temperature steam environment, rubber parts in a braking system, seals in a radiator.
Nitrile Butadiene Rubber (NBR)
Nitrile Rubber is composed of acrylonitrile and butadiene. The content of acrylonitrile ranges from 18% to 50%. The higher content of acrylonitrile, the better resistance to hydrocarbon fuel oil of petrochemical oil, while worse performance in low temperature. Generally using temperature is - 25 ~ 100 degree. Nitrile rubber is one of the most commonly used rubbers for oil seal and o-ring.
Advantages: good oil resistance, water resistance, solvent resistance and high pressure oil resistance, it has good compressibility, wear resistance and elongation.
Disadvantages: not suitable for using in a polar solvent, such as ketones, ozone, nitro hydrocarbon, MEK and chloroform.
Application: Used to produce fuel tank, lubrication oil tank and the rubber parts using in the fluid medium like hydraulic oil, gas, water, silicone oil, diester lubricating oil, etc., especially the sealing parts. As it were the most widely used and the lowest cost of rubber seals.