Classification of rubber

Classification of rubber

According to the morphology is divided into lumpy raw rubber, latex, liquid rubber and powder rubber. Latex is a colloidal moisture dispersion of rubber; Liquid rubber for rubber oligomer, unvulcanized before generally viscous liquid; Powder rubber is latex processing into powder form, for ingredients and processing production. Thermoplastic rubber, developed in the 1960s, is formed by a thermoplastic process without chemical vulcanization. Rubber is divided into general type and special type according to its use. It is an insulator. It does not conduct electricity easily, but it may become a conductor if it is exposed to water or different temperatures. Conductivity refers to the ease with which electrons in molecules or ions inside a substance conduct. According to the source of raw materials and methods: rubber can be divided into natural rubber and synthetic rubber two categories. The consumption of natural rubber accounts for 1/3, the consumption of synthetic rubber accounts for 2/3.

According to the appearance of rubber: rubber can be divided into solid rubber (also known as dry rubber), latex rubber (latex for short), liquid rubber and powder rubber four categories.

According to the performance and use of rubber: in addition to natural rubber, synthetic rubber can be divided into general synthetic rubber, semi-general synthetic rubber, special synthetic rubber and special synthetic rubber.

According to the physical form of rubber: rubber can be divided into hard and soft rubber, raw rubber and mixed rubber and so on.

According to performance and use: general rubber and special rubber

Natural rubber(NR) basically comes from three leaves rubber tree, when the skin of this kind of rubber tree is cut, can outflow milky white juice, call latex, latex by condensation, washing, molding, dry natural rubber. Synthetic rubber is made by artificial synthetic methods, using different raw materials (monomer) can be synthesized into different kinds of rubber. 1900-1910 chemist C.D. Harris (Harris) determined that the structure of natural rubber is the polymer of isoprene, which opened up the way for artificial rubber. In 1910, Russian chemist SV Lebedev (Lebedev, 1874-1934) made 1, 3-butadiene polymerization into sodium butadiene rubber with metal sodium as initiator. Later, many new varieties of synthetic rubber appeared successively, such as butadiene rubber, neoprene rubber, styrene butadiene and so on. The output of synthetic rubber has greatly exceeded that of natural rubber, among which the largest output is styrene butadiene rubber.

General rubber

Refers to partial or total replacement of natural rubber rubber rubber, such as styrene butadiene rubber, butadiene rubber, isoprene rubber, etc., mainly used in the manufacture of tires and general industrial rubber products. General rubber is in great demand and is the main variety of synthetic rubber.

Styrene butadiene rubber (SBR)

Styrene butadiene rubber(SBR) is made by copolymerization of butadiene and styrene, is the largest yield of general synthetic rubber, latex styrene butadiene rubber, soluble styrene butadiene rubber and thermoplastic rubber (SBR).

Nitrile rubber (NBR)

Nitrile rubber(NBR) is composed of butadiene and acrylonitrile by emulsion copolymerization of polymers, nitrile rubber, with its excellent oil resistance and yarrow, according to the oil resistance after polysulfide rubber, acrylate rubber and fluorine rubber, nitrile rubber also has good abrasion resistance, aging resistance and gas tightness, ozone resistance, electrical insulation and cold resistance is poor, and electrical conductivity is better. Therefore, it is widely used in the rubber industry. Nitrile rubber is mainly used for oil resistant products, such as various sealing products. Other as PVC modifier and PVC and used as flame retardant products, and phenolic and used as structural adhesive, do antistatic good rubber products, etc.

Silicone rubber

Silicone rubber is composed of silicon and oxygen atoms to form the main chain, and the side chain is carbon-containing groups. The largest amount of silicone rubber is the side chain of ethylene. Both heat resistance and cold resistance, the use of temperature between 100-300℃, it has excellent weather resistance and ozone resistance to use good insulation. Disadvantages are low strength, poor tear resistance, wear resistance is also poor. Silicone rubber is mainly used in aviation industry, electrical industry, food industry and medical industry.

Butadiene rubber

It is made by solution polymerization of butadiene, butadiene rubber has special excellent cold resistance, wear resistance and elasticity, but also has good aging resistance. The vast majority of butadiene rubber is used in the production of tires, and a small part of it is used in the manufacture of cold-resistant products, buffer materials, tapes, rubber shoes and so on. The disadvantage of butadiene rubber is poor tear resistance and poor wet slip resistance.

Isoamyl rubber

Isoprene rubber is short for polyisoprene rubber, which is produced by solution polymerization. Isoprene rubber, like natural rubber, has good elasticity and wear resistance, excellent heat resistance and good chemical stability. The strength of isoprene rubber (before processing) is significantly lower than that of natural rubber, but the quality uniformity and processing property of isoprene rubber are better than that of natural rubber. Isoprene rubber can replace natural rubber to make truck tires and off-road tires can also be used to produce a variety of rubber products.

Ethylene propylene rubber(EPDM)

Ethylene propylene rubber (EPDM)is synthesized with ethylene and propylene as the main raw materials. It has excellent aging resistance, electrical insulation performance and ozone resistance. EPDM can be filled with oil and carbon black, the product price is low, EPDM chemical stability is good, wear resistance, elasticity, oil resistance and styrene butadiene rubber close. EPDM has a wide range of uses. It can be used as tire side, rubber strip, inner tube and auto parts. It can also be used as wire, cable wrapping and high voltage, ultra-high voltage insulation material. Can also manufacture rubber shoes, sanitary products and other light products.

Neoprene (CR)

It is made of chlorobutadiene as the main raw material by homopolymerization or copolymerization of a small amount of other monomers. Such as high tensile strength, heat resistance, light resistance, aging resistance is good, oil resistance is better than natural rubber, styrene butadiene rubber, butadiene rubber. It has strong fire resistance and excellent retardation resistance. It has high chemical stability and good water resistance. The disadvantage of neoprene rubber is electrical insulation performance, poor cold resistance, raw rubber in storage is not stable. Neoprene rubber is widely used for making transport belts and belts, wrapping materials for wires and cables, making oil-resistant rubber hoses, gaskets and chemical resistant equipment linings.