Classification according to source and use: natural rubber, synthetic rubber; Synthetic rubber is also divided into general synthetic rubber and special synthetic rubber.
Natural rubber
Natural rubber mainly comes from clover rubber trees. When the skin of this rubber tree is cut, milky juice, called latex, will flow out. The latex can be condensed, washed, shaped and dried to obtain natural rubber.
Synthetic rubber is made by artificial synthesis. Different kinds of rubber can be synthesized by using different raw materials (monomers). From 1900 to 1910, chemist C.D. Harris determined that the structure of natural rubber was a polymer of isoprene, which opened a way for synthetic rubber. In 1910, Russian chemist SV Lebedev (1874-1934) polymerized 1,3-butadiene into sodium butadiene rubber with metal sodium as initiator. Later, many new synthetic rubber varieties emerged, such as cis polybutadiene rubber, neoprene rubber, styrene butadiene rubber, etc. The output of synthetic rubber has greatly exceeded that of natural rubber, among which styrene butadiene rubber has the largest output
General purpose rubber
It refers to the rubber that partially or completely replaces natural rubber, such as styrene butadiene rubber, cis-1,4-polybutadiene rubber, isoprene rubber, etc., and is mainly used to manufacture tires and general industrial rubber products. The demand for general rubber is large, and it is the main variety of synthetic rubber.
Cis polybutadiene rubber
It is prepared by solution polymerization of butadiene. cis polybutadiene rubber has particularly excellent cold resistance, abrasion resistance, elasticity and good aging resistance. The majority of cis-1,4-polybutadiene rubber is used in the production of tires, and a small part is used in the production of cold resistant products, cushioning materials, tapes, rubber shoes, etc. The disadvantages of cis polybutadiene rubber are poor tear resistance and wet skid resistance.
Isoprene rubber
Isoprene rubber is the abbreviation of polyisoprene rubber, which is produced by solution polymerization. Like natural rubber, isoprene rubber has good elasticity, wear resistance, excellent heat resistance and good chemical stability. The strength of raw isoprene rubber (before processing) is significantly lower than that of natural rubber, but its quality uniformity and processing performance are better than those of natural rubber. Isoprene rubber can replace natural rubber to make truck tire and off-road tire, and can also be used to produce various rubber products.
Ethylene propylene rubber
Ethylene propylene rubber is synthesized with ethylene and propylene as the main raw materials, with outstanding aging resistance, electrical insulation and ozone resistance. Ethylene propylene rubber can be filled with a large amount of oil and carbon black. The product price is low. Ethylene propylene rubber has good chemical stability, and its wear resistance, elasticity, and oil resistance are similar to those of styrene butadiene rubber. Ethylene propylene rubber is widely used as tire sidewall, rubber strip, inner tube and auto parts, as well as wire, cable sheath and high-voltage and ultra-high voltage insulation materials. It can also manufacture light colored products such as rubber shoes and sanitary products
