The origin and application characteristics of rubber
Sources and application characteristics of different types of rubber
The comprehensive performance of different types of rubber is good and it is widely used. The main types are: ① Natural rubber. It is made from the latex of Hevea brasiliensis, and its basic chemical composition is cis-polyisoprene. It has good elasticity, high strength and good comprehensive performance. ② Isoprene rubber. Its full name is cis-1,4-polyisoprene rubber. It is a high-cis synthetic rubber made from isoprene. Because its structure and performance are similar to those of natural rubber, it is also called synthetic natural rubber. ③ Styrene-butadiene rubber. It is referred to as SBR, which is made by copolymerization of butadiene and styrene. According to the production method, it is divided into emulsion polymerization styrene-butadiene rubber and solution polymerization styrene-butadiene rubber. It has good comprehensive performance and chemical stability. ④ Butadiene rubber. Its full name is cis-1,4-polybutadiene rubber, referred to as BR, which is made by polymerization of butadiene. Compared with other general-purpose rubbers, the cold resistance, wear resistance and elasticity of vulcanized cis-butadiene rubber are particularly excellent, with less heat generation under dynamic load, good aging resistance, and easy to be used with natural rubber, chloroprene rubber, nitrile rubber, etc.
Sources and application characteristics of different special rubbers
Special rubber refers to rubber with certain special properties. There are mainly: ① Chloroprene rubber. Referred to as CR, it is made by polymerization of chloroprene. It has good comprehensive properties, oil resistance, flame resistance, oxidation resistance and ozone resistance. However, its density is relatively large, it is easy to crystallize and harden at room temperature, has poor storage and poor cold resistance. ② Nitrile rubber. Referred to as NBR, it is made by copolymerization of butadiene and acrylonitrile. It has good oil resistance and aging resistance, and can be used for a long time in air at 120°C or in oil at 150°C. In addition, it also has water resistance, air tightness and excellent bonding properties. ③ Silicone rubber. The main chain is composed of alternating silicon and oxygen atoms, with organic groups on the silicon atoms. Resistant to high and low temperatures, ozone, and good electrical insulation. ④ Fluororubber. A synthetic rubber containing fluorine atoms in the molecular structure. It is usually expressed by the number of fluorine atoms in the fluorine-containing unit in the copolymer, such as fluororubber 23, which is a copolymer of vinylidene fluoride and trifluorochloroethylene. Fluororubber is resistant to high temperatures, oils, and chemical corrosion. ⑤ Polysulfide rubber. It is formed by the condensation of dihaloalkane and polysulfide of alkali metal or alkaline earth metal. It has excellent oil resistance and solvent resistance, but low strength, poor aging resistance and processability, and odor. It is often used in combination with nitrile rubber. In addition, there are polyurethane rubber, chlorohydrin rubber, acrylic rubber, etc.
The comprehensive performance of different types of rubber is good and it is widely used. The main types are: ① Natural rubber. It is made from the latex of Hevea brasiliensis, and its basic chemical composition is cis-polyisoprene. It has good elasticity, high strength and good comprehensive performance. ② Isoprene rubber. Its full name is cis-1,4-polyisoprene rubber. It is a high-cis synthetic rubber made from isoprene. Because its structure and performance are similar to those of natural rubber, it is also called synthetic natural rubber. ③ Styrene-butadiene rubber. It is referred to as SBR, which is made by copolymerization of butadiene and styrene. According to the production method, it is divided into emulsion polymerization styrene-butadiene rubber and solution polymerization styrene-butadiene rubber. It has good comprehensive performance and chemical stability. ④ Butadiene rubber. Its full name is cis-1,4-polybutadiene rubber, referred to as BR, which is made by polymerization of butadiene. Compared with other general-purpose rubbers, the cold resistance, wear resistance and elasticity of vulcanized cis-butadiene rubber are particularly excellent, with less heat generation under dynamic load, good aging resistance, and easy to be used with natural rubber, chloroprene rubber, nitrile rubber, etc.
Sources and application characteristics of different special rubbers
Special rubber refers to rubber with certain special properties. There are mainly: ① Chloroprene rubber. Referred to as CR, it is made by polymerization of chloroprene. It has good comprehensive properties, oil resistance, flame resistance, oxidation resistance and ozone resistance. However, its density is relatively large, it is easy to crystallize and harden at room temperature, has poor storage and poor cold resistance. ② Nitrile rubber. Referred to as NBR, it is made by copolymerization of butadiene and acrylonitrile. It has good oil resistance and aging resistance, and can be used for a long time in air at 120°C or in oil at 150°C. In addition, it also has water resistance, air tightness and excellent bonding properties. ③ Silicone rubber. The main chain is composed of alternating silicon and oxygen atoms, with organic groups on the silicon atoms. Resistant to high and low temperatures, ozone, and good electrical insulation. ④ Fluororubber. A synthetic rubber containing fluorine atoms in the molecular structure. It is usually expressed by the number of fluorine atoms in the fluorine-containing unit in the copolymer, such as fluororubber 23, which is a copolymer of vinylidene fluoride and trifluorochloroethylene. Fluororubber is resistant to high temperatures, oils, and chemical corrosion. ⑤ Polysulfide rubber. It is formed by the condensation of dihaloalkane and polysulfide of alkali metal or alkaline earth metal. It has excellent oil resistance and solvent resistance, but low strength, poor aging resistance and processability, and odor. It is often used in combination with nitrile rubber. In addition, there are polyurethane rubber, chlorohydrin rubber, acrylic rubber, etc.