Rubber knowledge, how much do you know as a purchasing engineer?

1. Natural rubber (NR) is mainly rubber hydrocarbon (polyisoprene) and contains a small amount of protein, moisture, resin acid, sugar and inorganic salts. High elasticity, high tensile strength, excellent tear resistance and electrical insulation, good wear resistance and drought resistance, good processability, easy adhesion with other materials, and comprehensive performance superior to most synthetic rubbers. Disadvantages are poor anti-oxygen and anti-ozone ability and easy aging and deterioration; Poor oil resistance and solvent resistance, low acid and alkali corrosion resistance; Heat resistance is not high. Temperature range: about -60℃ ~+80℃. Manufacture general products such as tires, rubber shoes, hoses, tapes, insulation layers and sheaths of wires and cables. It is especially suitable for manufacturing torsional vibration eliminators, engine shock absorbers, machine supports, rubber-metal suspension elements, diaphragms and molded products.

2. Styrene-butadiene rubber (SBR) copolymer of butadiene and styrene. Its performance is close to that of natural rubber, and it is the general synthetic rubber with the largest output at present. Its characteristics are wear resistance, aging resistance and heat resistance, and its texture is more uniform than that of natural rubber. Disadvantages are: low elasticity, poor buckling resistance and tear resistance; Poor processability, especially poor self-adhesion, and low strength of raw rubber. Working temperature range: about -50℃ ~+ 100℃. Mainly used to replace natural rubber to make tires, rubber sheets, rubber hoses, rubber shoes and other general products.

3. Butadiene rubber (BR) is a cis-structure rubber polymerized from butadiene. Advantages: excellent elasticity and wear resistance, good aging resistance, excellent low temperature resistance, low calorific value under dynamic load and easy metal bonding. Disadvantages are low strength, poor tear resistance, poor machinability and self-adhesion. Service temperature range: about -60℃ ~+ 100℃. Generally used with natural rubber or styrene-butadiene rubber, it is mainly used to make tire treads, conveyor belts and special cold-resistant products.

4. Isoprene rubber (IR) is a cis-structure rubber polymerized from isoprene monomer. The chemical composition, three-dimensional structure and properties are similar to those of natural rubber, so it is called synthetic natural rubber. It has most advantages of natural rubber, its aging resistance is better than that of natural rubber, its elasticity and strength are slightly lower than that of natural rubber, its processability is poor and its cost is higher. Service temperature range: about -50℃ ~+ 100℃ can replace natural rubber to make general products such as tires, rubber overshoes, rubber hoses and adhesive tapes.

5. Chloroprene rubber (CR) is a polymer made by emulsion polymerization with chloroprene as monomer. This kind of rubber contains chlorine atoms in its molecules, so compared with other ordinary rubbers, it has the advantages of excellent oxidation resistance, ozone resistance, incombustibility, self-extinguishing in case of fire, oil resistance, solvent resistance, acid and alkali resistance, aging resistance and good air tightness. Its physical and mechanical properties are also better than natural rubber, so it can be used as general rubber and special rubber. The main disadvantages are poor cold resistance, heavy specific gravity, high relative cost, poor electrical insulation, and easy to roll, scorch and stick to the mold during processing. In addition, raw rubber has poor stability and is not easy to store. Working temperature range: about -45℃ ~+ 100℃. Mainly used for manufacturing cable sheaths, various protective sleeves and protective sleeves that require ozone resistance and high aging resistance; Oil-resistant and chemical-resistant rubber hose, adhesive tape and chemical lining; Refractory rubber products for underground mining, as well as various molded products, sealing rings, gaskets, adhesives, etc.

6. Butyl rubber (IIR) is a copolymer of isobutylene and a small amount of isoprene or butadiene. The biggest feature is good air tightness, ozone resistance, aging resistance and high heat resistance, and the long-term working temperature can be130℃; Resistant to inorganic strong acids (such as sulfuric acid and nitric acid). ) and common organic solvents, which have good vibration absorption and damping characteristics and excellent electrical insulation. Disadvantages are poor elasticity, poor processability, slow vulcanization speed, poor adhesion and poor oil resistance. Service temperature range: about -40℃ ~+ 120℃. Mainly used as inner tube, water tyre, balloon, wire and cable insulation layer, chemical equipment lining and shock-proof products, heat-resistant conveyor belt and heat-resistant aging adhesive tape products.

7. Ding Qing Rubber (NBR) copolymer of butadiene and acrylonitrile. It is characterized by excellent gasoline and aliphatic hydrocarbon oil resistance, second only to polysulfide rubber, acrylate and fluororubber, and superior to other general rubber. Good heat resistance, air tightness, wear resistance, water resistance and strong adhesion. Disadvantages are poor cold resistance and ozone resistance, low strength and elasticity, poor acid resistance, poor electrical insulation and poor polar solvent resistance. Working temperature range: about -30℃ ~+ 100℃. It is mainly used to manufacture various oil-resistant products, such as rubber pipes and sealing products.

8. Hydrogenated Ding Qing rubber (HNBR) copolymer of butadiene and acrylonitrile. It is obtained by completely or partially hydrogenating the double bonds in butadiene of nitrile rubber. It is characterized by high mechanical strength and wear resistance. When crosslinked with peroxide, its heat resistance is better than that of NBR, and other properties are the same as those of Ding Qing rubber. The disadvantage is that the price is higher. Working temperature range: about -30℃ ~+ 150℃. Mainly used for oil-resistant and high-temperature resistant sealing products.

9. Ethylene-propylene rubber (EPM\EPDM) Copolymers of ethylene and propylene are generally divided into EPDM and EPDM. It is characterized by excellent ozone resistance, ultraviolet resistance, weather resistance and aging resistance, ranking first among general rubber. Good electrical insulation, chemical resistance, impact elasticity, acid and alkali resistance, small specific gravity and high filling. Heat resistance can reach 150℃, polar solvents-ketones, esters, etc. , but not resistant to aliphatic hydrocarbons and aromatic hydrocarbons. Other physical and mechanical properties are slightly inferior to natural rubber and superior to styrene-butadiene rubber. The disadvantage is that self-adhesion and mutual adhesion are poor, and it is not easy to bond. Working temperature range: about -50℃ ~+ 150℃. Mainly used as chemical equipment lining, wire and cable sheath, steam hose, heat-resistant conveyor belt, rubber products for automobiles and other industrial products.

10. Silicone rubber (Q) is a special rubber with silicon and oxygen atoms in its main chain, in which silicon plays a major role. Its main characteristics are high temperature resistance (up to 300℃) and low temperature resistance (as low as-100℃), and it is the rubber with the best cold and high temperature resistance at present. At the same time, it has excellent electrical insulation, high stability to thermal oxidation and ozone, and great chemical inertia. Disadvantages are low mechanical strength, poor oil resistance, solvent resistance, acid and alkali resistance, difficult vulcanization and high price. Service temperature: -60℃ ~+200℃. Mainly used for making high and low temperature resistant products (hoses, seals, etc.). ) and high temperature wire and cable insulation layer. Because it is non-toxic and tasteless, it is also used in food and medical industries.

1 1. Fluorocarbon (FPM) is an organic elastomer formed by copolymerization of fluorine-containing monomers. It is characterized by high temperature resistance up to 300℃, acid and alkali resistance, oil resistance, radiation resistance and high vacuum. Excellent electrical insulation, mechanical properties, chemical corrosion resistance, ozone resistance and atmospheric aging resistance. The disadvantages are poor processability, high price, poor cold resistance and low elastic permeability. Temperature range: -20℃ ~+200℃. It is mainly used in the national defense industry to manufacture vacuum-resistant, high-temperature resistant and chemical-resistant sealing materials, hoses or other parts on airplanes and rockets, as well as in the automobile industry.

12. Polyurethane rubber (AU\EU) is an elastomer polymerized from polyester (or polyether) and diisocyanate. It is characterized by good wear resistance and is the best among all kinds of rubber; High strength, good elasticity and excellent oil resistance. Ozone resistance, aging resistance and air tightness are also excellent. Disadvantages are poor temperature resistance, poor water and alkali resistance, and poor tolerance to aromatic hydrocarbons, chlorinated hydrocarbons, ketones, esters, alcohols and other solvents. Temperature range: about -30℃ ~+80℃. Tires are made of wear-resistant, high-strength and oil-resistant parts, gaskets, shock-proof products and rubber products.

13. Acrylate rubber (ACM\AEM) It is a polymer of ethyl acrylate or butyl acrylate. Its characteristics are good heat resistance and oil resistance, and its performance is stable in lubricating oil containing sulfur, phosphorus and chlorine additives. At the same time, it has excellent aging resistance, oxygen and ozone resistance, ultraviolet resistance and air tightness. Disadvantages are poor cold resistance, water resistance, steam resistance, organic and inorganic acids and bases. It swells badly in water-soluble solutions such as methanol, ethylene glycol and ketone esters. At the same time, the elasticity and wear resistance are poor, the electrical insulation is poor, and the processability is poor. Working temperature range: about -25℃ ~+ 180℃. It can be used to make oil-resistant, heat-resistant and aging-resistant products, such as seals, hoses and chemical linings.

14. chlorosulfonated polyethylene rubber (CSM) is an elastic polymer obtained by chlorination and sulfonation of polyethylene. Excellent ozone resistance and weather resistance, superior to other rubbers. Good flame retardancy, heat resistance, solvent resistance, resistance to most chemicals and acid and alkali resistance. The electrical insulation is acceptable and the wear resistance is similar to that of styrene-butadiene rubber. Disadvantages are poor tear resistance and poor processability. Working temperature range: about -20℃ ~+ 120℃. It can be used as sealing material on ozone generator to make oil-resistant seals, wire and cable sheaths, oil-resistant rubber products and chemical lining.

15. epichlorohydrin rubber (CO\ECO) is a polymer formed by homopolymerization of epichlorohydrin or copolymerization of epichlorohydrin and ethylene oxide. It is characterized by excellent solvent resistance to aliphatic hydrocarbons and chlorinated hydrocarbons, alkali resistance, water resistance and aging resistance, ozone resistance, weather resistance and high air tightness. Disadvantages are low strength, poor elasticity and poor electrical insulation. Service temperature range: about -40℃ ~+ 140℃. It can be used as rubber hose, seal, film and container liner, oil tank, rubber roller, oil seal, water seal and so on.

16. Chlorinated polyethylene rubber (CM or CPE) is an elastic polymer made of polyethylene by chlorination reaction. Its performance is close to chlorosulfonated polyethylene rubber, which is characterized by good fluidity and easy processing. It has excellent weather resistance, ozone resistance and corona resistance, as well as good heat resistance, acid and alkali resistance and oil resistance. Disadvantages are poor elasticity, large compression deformation and low electrical insulation. Working temperature range: about -20℃ ~+ 120℃. Wire and cable sheath, rubber hose, adhesive tape, rubber roller chemical lining, etc.