Rubber is a kind of high elastic polymer material, under the action of a small external force, it can show a high degree of deformability, and after the external force is removed, it can return to its original shape. Due to the high elasticity of rubber, it is widely used in cushioning, shockproof, dynamic sealing, etc. The application in the printing industry includes various rubber rollers and printing blankets. With the progress of the rubber industry, rubber products have developed from a single use of natural rubber to a variety of synthetic rubbers.
1. Natural rubber
Natural rubber is dominated by rubber hydrocarbons (polyisoprene), containing a small amount of protein, water, resin acids, sugars and inorganic salts. Natural rubber has large elasticity, high tensile strength, excellent tear resistance and electrical insulation, good wear resistance and drought resistance, good processability, natural rubber is easy to bond with other materials, and its overall performance is better than most synthetics rubber. The shortcomings of natural rubber are poor resistance to oxygen and ozone, easy to aging and deterioration; poor resistance to oil and solvents, low resistance to acid and alkali, low corrosion resistance; low heat resistance. The operating temperature range of natural rubber: about -60℃~+80℃. Natural rubber is used to make tires, rubber shoes, hoses, tapes, insulating layers and sheaths of wires and cables, and other general products. Natural rubber is particularly suitable for the manufacture of torsional vibration eliminators, engine shock absorbers, machine supports, rubber-metal suspension elements, diaphragms, and molded products.
2. SBR
SBR is a copolymer of butadiene and styrene. The performance of styrene-butadiene rubber is close to that of natural rubber, and it is currently the largest production of general-purpose synthetic rubber. The characteristics of styrene-butadiene rubber are that its wear resistance, aging resistance and heat resistance exceed natural rubber, and its texture is more uniform than natural rubber. The disadvantages of styrene-butadiene rubber are: low elasticity, poor flex resistance and tear resistance; poor processing performance, especially poor self-adhesiveness and low green rubber strength. The temperature range of styrene-butadiene rubber: about -50℃~+100℃. Styrene butadiene rubber is mainly used to replace natural rubber to make tires, rubber sheets, hoses, rubber shoes and other general products
3. Nitrile rubber
Nitrile rubber is a copolymer of butadiene and acrylonitrile. Nitrile rubber is characterized by its excellent resistance to gasoline and aliphatic hydrocarbon oils, second only to polysulfide rubber, acrylic ester and fluorine rubber, while nitrile rubber is superior to other general-purpose rubbers. Good heat resistance, good air tightness, wear resistance and water resistance, and strong adhesion. The disadvantages of nitrile rubber are poor cold resistance and ozone resistance, low strength and elasticity, poor acid resistance, poor electrical insulation, and poor resistance to polar solvents. The temperature range of nitrile rubber: about -30℃~+100℃. Nitrile rubber is mainly used to manufacture various oil-resistant products, such as hoses, sealing products, rubber rollers, etc.
4. Hydrogenated nitrile rubber
Hydrogenated nitrile rubber is a copolymer of butadiene and acrylonitrile. The hydrogenated nitrile rubber is obtained by fully or partially hydrogenating the double bonds in the butadiene of NBR. Hydrogenated nitrile rubber is characterized by high mechanical strength and abrasion resistance, heat resistance is better than NBR when crosslinked with peroxide, and other properties are the same as nitrile rubber. The disadvantage of hydrogenated nitrile rubber is its higher price. The temperature range of hydrogenated nitrile rubber: about -30℃~+150℃. Hydrogenated nitrile rubber is mainly used for oil-resistant and high-temperature-resistant sealing products.
5. Ethylene propylene rubber
Ethylene propylene rubber is a copolymer of ethylene and propylene, and is generally divided into two yuan ethylene propylene rubber and three yuan ethylene propylene rubber. Ethylene-propylene rubber is characterized by excellent ozone resistance, ultraviolet resistance, weather resistance and aging resistance, ranking first among general-purpose rubbers. Ethylene-propylene rubber has good electrical insulation, chemical resistance, impact elasticity, acid and alkali resistance, low specific gravity, and can be used for high filling. The heat resistance can reach 150°C, and it is resistant to polar solvents-ketones, esters, etc., but ethylene propylene rubber is not resistant to aliphatic hydrocarbons and aromatic hydrocarbons. The other physical and mechanical properties of ethylene propylene rubber are slightly inferior to natural rubber and superior to styrene butadiene rubber. The disadvantage of ethylene-propylene rubber is that it has poor self-adhesion and mutual adhesion, and it is not easy to bond. The temperature range of ethylene propylene rubber: about -50℃~+150℃. Ethylene-propylene rubber is mainly used as chemical equipment lining, wire and cable sheathing, steam hose, heat-resistant conveyor belt, automobile rubber products and other industrial products.
6. Silicone rubber
Silicone rubber is a special rubber with silicon and oxygen atoms in the main chain. Silicon element plays a major role in silicone rubber. The main characteristics of silicone rubber are both high temperature resistance (up to 300°C) and low temperature resistance (lowest -100°C). It is currently the best high temperature resistant rubber; at the same time, silicone rubber has excellent electrical insulation and is stable to thermal oxidation and ozone. It is highly resistant and chemically inert. The disadvantages of silicone rubber are low mechanical strength, poor oil resistance, solvent resistance, acid and alkali resistance, difficult to vulcanize, and more expensive. Silicone rubber operating temperature: -60℃~+200℃. Silicone rubber is mainly used to make high and low temperature resistant products (hoses, seals, etc.), and high temperature resistant wire and cable insulation. Because it is non-toxic and tasteless, silicone rubber is also used in the food and medical industries.
7. Polyurethane rubber
Polyurethane rubber has an elastomer formed by the polymerization of polyester (or polyether) and diisocyanate compounds. Polyurethane rubber is characterized by good abrasion resistance, which is the best among all kinds of rubber; polyurethane rubber has high strength, good elasticity and excellent oil resistance. Polyurethane rubber is also excellent in ozone resistance, aging resistance, and air tightness. The disadvantages of polyurethane rubber are poor temperature resistance, poor water and alkali resistance, and poor resistance to aromatic hydrocarbons, chlorinated hydrocarbons, and solvents such as ketones, esters, and alcohols. The use temperature range of polyurethane rubber: about -30℃~+80℃. Polyurethane rubber is used to make tires close to parts, gaskets, shockproof products, rubber rollers, and wear-resistant, high-strength and oil-resistant rubber products.
Post time: Jul-07-2021