Synthetic rubber is an artificially produced, elastic material , a polymer derived from petroleum derivatives. In the United States, approximately 32 million tons of rubber are produced annually, two-thirds of which is synthetic. Like natural rubber, synthetic rubber is widely used in the automotive industry, for example in tires, window and door panels, rubber seals, hoses, belts, mats, and floor coverings. Synthetic rubber possesses numerous physical and chemical properties that improve the reliability of certain products or applications. It is superior to natural rubber in two key aspects: thermal stability and resistance to oils and related compounds. Furthermore, it is more resistant to oxidizing agents such as oxygen and ozone, which can shorten the lifespan of products like tires.
History of synthetic rubber
From the 1890s onward, the increasing popularity of bicycles, and especially their tires, led to a rising demand for rubber. In 1909, a team led by Fritz Hoffmann at Bayer’s laboratory in Elberfeld, Germany, succeeded in polymerizing isoprene and thus producing the first synthetic rubber.
In 1930, Lebedev, the American Wallace Carthars, and the German scientist Hermann Staudinger independently published the results of their research, which led to the development of one of the first synthetic rubbers: chloroprene rubber. In 1931, DuPont, under the direction of Bolton, successfully developed chloroprene rubber. Chloroprene rubber is characterized by extremely high resistance to heat and chemical corrosion, for example from oil and gasoline, and is frequently used in the manufacture of fuel hoses and as mechanical insulation. Thiocor used this name for a dichloroethane-based rubber product that competed with chloroprene rubber.
In 1935, German chemists synthesized the first synthetic rubber, known as nitrile rubber. Nitrile rubber is a copolymer, meaning it is produced by the alternating polymerization of two monomers. Other brand names include Corusel , developed by Simon’s father in 1935, and Soupbrin, developed by Soviet researchers in 1940 .
Second World War
During World War II, when Japan occupied large parts of Asia, particularly the British colonies in Southeast Asia, Malaya (present-day Malaysia) and the Dutch East Indies (present-day Indonesia), the Axis powers controlled almost all of the world’s limited supplies of natural rubber, and as a result, the production of synthetic rubber in the United States expanded rapidly.
Targets of Nazi Germany’s close-range bombing raids included the Schoppa plant (annual production 50,000 tons) and the Holz rubber plant near Recklinghausen (annual production 30,000 tons, corresponding to 17% of total production), as well as the tire and hose factory of the Cologne Rubber Company on the east bank of the Rhine at Deutz . On August 23, 1944, a rubber plant in Ferrara, Italy (near the bridge over the Rhine ) was bombed. The plant in Leverkusen (annual production 5,000 tons) was also hit. On March 5, 1944, a rubber plant under construction in Auschwitz, in occupied Poland, operated by Farben AG with forced laborers from the Auschwitz III (Monowitz) concentration camp, was bombed.
Man
The most common type of synthetic rubber is styrene-butadiene rubber (SBR), a copolymer of styrene and 1,3-butadiene. Other types of synthetic rubber include:
- Polyisoprene is obtained by polymerization of isoprene.
- Chloroprene rubber is obtained by polymerization of 2-chlorobutadiene.
- Nitrile rubber is made from cyanobutadiene or 2-acrylonitrile and butadiene.
By mixing different monomers and catalysts, a variety of compounds of this type can be obtained , thereby controlling the stereochemistry.
Polyisobutylene, also known as butyl rubber, is widely used in tire inner tubes and liners due to its effective airtightness. However, its elasticity is significantly lower than that of polybutadiene cysteine (PBC), which is often used in tire sidewalls to reduce energy loss and heat buildup. In fact, PBC’s superior elasticity has led to its use in the manufacture of American footballs. Chlorosulfonated polyethylene (Hypalon) is a widely used rubber found in exterior building materials, such as roofing. Synthetic rubbers like ethylene propylene rubber (EPR) can also be used for electrical insulation.
silicone rubber
Silicone rubber is a synthetic, flexible material made from silicone polymers. It has a wide range of industrial applications and is available in various compositions. Silicone rubber typically consists of one or two components and may contain fillers to improve its properties or reduce costs. Overall, silicone rubber offers numerous advantages , including chemical inertness, good stability, and resistance to environmental influences and extreme temperatures.
Natural rubber and synthetic rubber
Natural rubber is obtained from the sap of the Brazilian rubber tree and consists mainly of polyisoprene .
Synthetic rubber, like other polymers, is made from various monomers derived from petroleum.
Some synthetic rubbers are less susceptible to ozone depletion than natural rubber . Natural rubber is sensitive to ozone due to the double bonds in its structure, while some synthetic rubbers lack these bonds and are therefore more resistant to ozone depletion. Examples include fluorinated rubber (Viton), ethylene propylene diene monomer (EPDM), and butyl rubber.
Flexible thermoplastics are a new type of synthetic rubber that, unlike natural rubber and conventional vulcanized rubber, is easily molded. The structural stability of polyurethane is achieved through crystalline bonds, while the structural stability of SBS homopolymer is ensured by amorphous bonds.