Material description
merits and demerits
Routine use
nitrile rubber
Nitrile-butadiene rubber (abbreviation of nitrile-butadiene rubber)
(NBR)
It is polymerized from acrylonitrile and butadiene. Acrylonitrile content ranges from 18% to 50%. The higher the acrylonitrile content, the better the hydrocarbon-resistant fuel oil performance of petrochemical products, but the low-temperature performance is poor. The general temperature range is -25~ 100℃. NBR is one of the most commonly used rubbers for oil seals and O-rings.
Advantages:
? It has good oil resistance, water resistance, solvent resistance and high pressure oil resistance.
? Good compression deformation, wear resistance and elongation.
Disadvantages:
? Not suitable for polar solvents, such as ketone, ozone, nitrohydrocarbon, MEK and chloroform.
Used for manufacturing fuel tanks, lubricating oil tanks and rubber parts, especially seals, and used for fluid media such as petroleum hydraulic oil, gasoline, water, silicone grease, silicone oil, diester lubricating oil and ethylene glycol hydraulic oil. It can be said that it is the most widely used rubber seal with the lowest cost at present.
Hydrogenated nitrile rubber
HNBR
(hydrogenated nitrile)
Hydrogenated nitrile rubber is a kind of nitrile rubber with partial double chains removed after hydrogenation. After hydrogenation, the temperature resistance and weather resistance are much higher than those of ordinary nitrile rubber, and the oil resistance is similar to that of ordinary nitrile rubber. The general temperature range is -25~ 150℃.
Advantages:
? Compared with NBR, it has better wear resistance.
? Excellent corrosion resistance, tensile resistance, tear resistance and compression deformation.
? Good resistance to ozone, sunlight and other atmospheric conditions.
? Generally speaking, it is suitable for washing clothes or washing dishes.
Disadvantages:
? It is not recommended to use in alcohol, ester or aromatic solution.
Environmental protection refrigerant R 134a system seals are widely used in air conditioning and refrigeration industries.
? Automobile engine system seal.
EPDM
EPDM
(ethylene propylene rubber)
The main chain of ethylene propylene polymerization is not double-stranded, so it has excellent heat resistance, aging resistance, ozone resistance and stability, but sulfur cannot be added. In order to solve this problem, EPDM can be obtained by introducing a small amount of the third component with double chains into the main chain of EP and adding sulfur. The general temperature range is -50~ 150℃. Excellent resistance to polar solvents, such as alcohol, ketone, ethylene glycol and phospholipid hydraulic oil.
Advantages:
? It has good weather resistance and ozone resistance.
? Excellent water resistance and chemical resistance.
? Alcohol and ketone can be used.
? High temperature steam resistance, good air tightness.
Disadvantages:
? Not recommended for food or contact with aromatic hydrogen.
Seals in high temperature water vapor environment.
? Sanitary ware seals or parts.
? Rubber parts in braking system.
? Seals in radiator (automobile water tank).
silicon rubber
International system of units of measurement
(silicone rubber)
The main chain of silica gel is composed of silicon (-si-o-si). Excellent heat resistance, cold resistance, ozone resistance and atmospheric aging resistance. It has good electrical insulation performance. The tensile strength is worse than that of ordinary rubber, and there is no oil resistance.
Advantages:
? The tensile strength can reach 1500PSI and the tear strength can reach 88LBS.
? Good elasticity and good compression deformation.
? Good resistance to neutral solvents.
? Excellent heat resistance.
? It has excellent cold resistance.
? Excellent ozone and oxidation corrosion resistance.
? Excellent electrical insulation performance
? Good heat insulation and heat dissipation performance.
Disadvantages:
? It is not recommended to use in most concentrated solvents, oils, concentrated acids and diluted sodium hydroxide.
Seals or rubber parts used in household appliances industry, such as rubber parts in electric cookers, irons and microwave ovens.
? Seals or rubber parts in electronic industry, such as mobile phone keys, shock absorbers in DVD, and seals in cable joints.
? Seals on various articles in contact with human body, such as kettles and drinking fountains.
viton
Equipment power policer (Facility Power Monitor)
(fluorocarbon rubber)
There are many types of rubber containing fluorine in the molecule according to fluorine content (that is, monomer structure). At present, the widely used hexafluororubber was first listed by DuPont under the trade name "Viton". High temperature resistance is better than silicone rubber, and it has excellent chemical resistance, resistance to most oils and solvents (except ketones and esters), weather resistance and ozone resistance; Cold resistance is poor, and the general temperature range is -20~250℃. The special formula can resist the low temperature of -40℃.
Advantages:
? The heat-resistant temperature is as high as 250℃
? It is resistant to most oils and solvents, especially all acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils.
Disadvantages:
? Not recommended for ketones, low molecular weight esters and mixtures containing nitrates.
Automobile, locomotive, diesel engine and fuel system.
? Seals for chemical plants.
Silicone fluorine rubber
FLS
(fluorinated silicone rubber)
Silicone fluororubber is fluorinated silicone rubber, and its general properties have the advantages of both fluororubber and silicone rubber. Its oil resistance, solvent resistance, fuel oil resistance and high and low temperature resistance are all good, and the general use temperature is -50~200℃.
Advantages:
? Suitable for special purposes, such as corrosion resistance of oxygen-containing chemicals, aromatic hydrogen-containing solvents and chlorine-containing solvents.
Disadvantages:
? It is not recommended to touch the solution of brake oil, ketone and bladder.
On the space machine.
Perfluorinated rubber
FFPM
(perfluoroelastomer)
Advantages:
? Optimum heat resistance
? Excellent chemical resistance
? Low outgassing characteristics
? Excellent plasma resistance.
Disadvantages:
? Low temperature resistance is poor.
? The price of raw materials is higher.
? It is difficult to produce.
Perfluorinated products are widely used in semiconductor industry and information-related industries, including PVC, CVD and etching processes in thin film technology and various high vacuum sealing processes.
chloroprene rubber
China Railway (China Railway)
(neoprene, polychloroprene)
It is polymerized from chlorobutene monomer. Vulcanized rubber has good elasticity and wear resistance, is not afraid of direct sunlight, especially has good atmospheric aging resistance, strong twisting resistance, resistance to refrigerants such as dichlorodifluoromethane and ammonia, resistance to dilute acid and silicone ester lubricating oil, and resistance to phosphate ester hydraulic oil. It is easy to crystallize and harden at low temperature and has poor storage stability. It has great expansion in mineral oil with low aniline point. The general temperature range is -50~ 150℃.
Advantages:
? Good elasticity and good compression deformation.
? This formula does not contain sulfur, so it is easy to make.
? It has anti-animal and vegetable oil properties.
? Physical properties will not be affected by neutral chemicals, esters, oils, various oils and solvents.
? It has flame retardant properties.
Disadvantages:
? Strong acids, nitro-hydrocarbons, esters, chloroform and ketones are not recommended.
R 12 refrigerant-resistant seal. ? Rubber parts or seals on household appliances.
? Suitable for making all kinds of parts that are in direct contact with the atmosphere, sunlight and ozone.
? Suitable for all kinds of fire-resistant and chemical-resistant rubber products.
butadiene-styrene rubber
S B R
(Styrene-butadiene copolymer)
Compared with natural rubber, the polymer of butadiene and styrene has uniform quality and less impurities, but its mechanical strength is weak, so it can be blended with natural rubber.
Advantages:
? Low-cost non-oil resistant material
? Good water resistance, good elasticity and hardness below 70.
? It has poor compression deformation at high hardness.
? Most neutral chemicals and dry and nutritious organic ketones can be used.
Disadvantages:
? Strong acids, ozone, oil, grease and most hydrocarbons are not recommended.
Widely used in tire industry, footwear industry, cloth industry and conveyor belt industry.
butyl rubber
Butyl rubber (abbreviation of Isobutylene-Isoprene Rubber)
(butyl rubber)
It is polymerized from isobutylene and a small amount of isoprene, and a small amount of unsaturated groups are reserved for sulfur addition. Because the sterically hindered molecules of methyl move less than other polymers, it has less air permeability, great resistance to heat, sunlight and ozone, and good electrical insulation. It is resistant to polar solvents, such as alcohol, ketone, ester and so on. The general temperature range is -54~ 1 10℃.
Advantages:
? Impermeability to most common gases.
? Good resistance to sunlight and ozone.
? May come into contact with animals or vegetable oils or oxidizable chemicals.
Disadvantages:
? It is used simultaneously with petroleum solvent, colloidal kerosene and aromatic hydrogen.
Used for manufacturing rubber parts of chemical corrosion resistant and vacuum equipment.
Chlorosulfonated polyethylene adhesive
Command and service module
(Hypalon, polyethylene)
Chlorosulfonated polyethylene is a kind of synthetic rubber, which was patented by DuPont. Good heat resistance, weather resistance and ozone resistance; Acid resistance is also good, and it is often used in places where antioxidant drugs (nitric acid and sulfuric acid) are used, and the general temperature range is -45~ 120℃.
Advantages:
? Good ozone resistance, oxidation resistance and flame retardancy.
? Physical properties are similar to chloroprene rubber, which has better acid resistance.
? Excellent wear resistance
? It has the same low friction surface as butyl rubber.
? Oil resistance and solvent resistance are between NBR and chloroprene rubber.
? It is recommended to use water to prevent leakage.
Disadvantages:
? Exposure to concentrated oxidizing acids, nitrohydrocarbons, esters, ketones and aromatic hydrogen is not recommended.
Acrylic rubber
The American computer association (association for computing machinery)
(polyacrylate rubber)
The elastomer polymerized with alkyl acrylate as the main component has good petrochemical oil resistance, high temperature resistance and weather resistance, but it is weak in mechanical strength, compression deformation rate and water resistance, which is slightly worse than the general oil-resistant adhesive. The general temperature range is -25~ 170℃.
Advantages:
? Suitable for automobile transmission oil.
? It has good oxidation resistance and weather resistance.
? It has the function of resisting bending deformation.
? Excellent oil-resistant product performance
? Suitable for automobile transmission system and power steering wheel.
Disadvantages:
? Not suitable for hot water.
? Not applicable to brake oil.
? Does not have the function of low temperature resistance.
? Not applicable to phosphate ester.
Automobile transmission system and power system seal.
natural rubber
NR
(natural rubber)
It is made of latex collected from rubber trees and is a polymer of isoprene. It has good wear resistance, high elasticity, breaking strength and elongation. Easy to age in air, sticky when heated, easy to swell and dissolve in mineral oil or gasoline, alkali-resistant but not strong acid-resistant.
It is the raw material for manufacturing adhesive tape, rubber hose and rubber overshoes, and is suitable for manufacturing damping components and products used in hydroxyl-containing liquids such as automobile brake oil and ethanol.
polyurethane rubber
polyurethane
(Polyurethane rubber)
The mechanical properties of polyurethane rubber are quite good, and its high hardness, high elasticity and wear resistance are incomparable with other rubbers. Aging resistance, ozone resistance and oil resistance are also quite good. The general temperature range is -45~90℃.
Advantages:
? Wear resistance and high pressure resistance
Disadvantages:
? Not resistant to high temperature
Industrial high-pressure wear-resistant seals, such as hydraulic cylinder seals.
? High voltage and high charge system
polytetrafluoroethylene
polytetrafluoroethylene
Polytetrafluoroethylene is commonly known as "the king of plastics". It has excellent chemical stability, corrosion resistance, sealing, high lubricity and non-stickiness, electrical insulation and good aging resistance. Can work at-180-250℃ for a long time.
Advantages:
? High and low temperature resistance
? Excellent corrosion resistance and aging resistance.
? Extremely high self-lubricating performance
? Good insulation performance
Disadvantages: lack of flexibility
In chemical industry, machinery, electronics, electrical appliances, military industry, aerospace, environmental protection, bridges and other national economic fields.