Rubber refers to a highly elastic polymer material with reversible deformation. It is elastic at room temperature, can produce large deformation under a small external force, and can return to its original state when the external force is removed.Rubber is a completely amorphous polymer, its glass transition temperature (T g) is low, the molecular weight is often large, more than hundreds of thousands.
Rubber is divided into natural rubber and synthetic rubber. Natural rubber is made of rubber extracted from hevea tree, hevea grass and other plants. Synthetic rubber is made by polymerization of various monomers. Rubber products are widely used in all aspects of industry or life.
General purpose rubber has good comprehensive properties and is widely used. There are mainly: ① natural rubber, from the latex of Hevea trefoil tree, the basic chemical composition of isoprene cis-polyisoprene. Good elasticity, high strength, good comprehensive performance. ② Isoprene rubber, the full name is cis-1, 4-polyisoprene rubber, made from isoprene high linear synthetic rubber, because of its structure and properties and natural rubber, it is also known as synthetic natural rubber. Styrene butadiene rubber, referred to as SBR, is copolymerized from butadiene and styrene. According to the production method is divided into emulsion polymerization styrene butadiene rubber and solution polymerization styrene butadiene rubber. Its comprehensive properties and chemical stability are good. ④ Butadiene rubber, the full name is cis-1, 4-polybutadiene rubber, referred to as BR, from butadiene polymerization. Compared with other general rubber, vulcanized butadiene rubber has excellent cold resistance, wear resistance and elasticity, less heating under dynamic load, good aging resistance, easy to use with natural rubber, neoprene rubber, nitrile rubber and so on. ⑤ Neoprene rubber, abbreviated CR, is prepared by chloroprene polymerization. It has good comprehensive performance, oil resistance, combustion resistance, oxidation resistance and ozone resistance. But its density is larger, easy to crystallize hard at room temperature, storage is not good, cold resistance is poor.
