Alkenes are hydrocarbon chemicals with a single double bond in their structure. These include ethylene, propylene, butylene, isobutylene, pentene, hexene, heptene and others. The use of alkenes is characteristic of many areas of industry, as well as for the national economy.
Due to the high chemical activity of the compounds with a double bond, they are widely used as raw materials for the chemical industry. Consider the use of alkenes on the example of
ethylene. Ethylene, which is at the beginning of the
homologous series of alkenes, is used to
produce ethylene glycol, which, in turn, is used to produce synthetic lavsan fiber, antifreeze, and
explosives. An important place in the application is played by the polymerization of ethylene. It passes at high temperature and pressure. Polymerizing, ethylene forms polyethylene, which is used as the basis for the production of plastics, synthetic rubbers and fuels. Polyethylene with short macromolecules is a liquid lubricant. If the number of links in a polyethylene molecule is 1.5-3 thousand, then bags, film, bottles, plastic utensils can be made from it. With an increase in the chain length to five to six thousand, polyethylene becomes a solid, durable material from which pipes and fittings are made.
Synthetic fibers are also obtained from other alkenes by polymerization. Polypropylene obtained from propene has high strength properties.
When ethylene reacts with hydrogen chloride, ethyl chloride is formed, which is used in medicine for local anesthesia. The use of alkenes is also associated with their ability to react with water, while forming alcohols. So, ethylene is obtained from ethylene during the hydration reaction . They have found their application as raw materials for the production of organic compounds, varnishes, plastics, cosmetic products and alkenes, which are formed from compounds with a double bond in the process of their oxidation with atmospheric oxygen. As a result of the addition reaction, haloalkanes are obtained from alkenes and halogens. Thus, dichloroethane is obtained from ethylene, which is used as a solvent for dissolving paints and varnishes, a disinfectant for granaries, soil, grain, and also as an adhesive for joining plastics.
Ethylene is also a raw material for the
production of acetic acid, ethylbenzene, styrene and many other industrially important chemical compounds. Its chemical properties determine its scope as the basis for obtaining all of these substances. High reactivity is due to the presence of a double bond. Addition reactions in alkenes occur via a double bond. As a result, the π bond splits and two σ bonds form in its place.
The use of alkenes is not limited to their use as raw materials to obtain a huge number of compounds. For example, ethylene is used in vegetable storages and in greenhouses to accelerate the ripening of fruits and vegetables, and also as a plant growth regulator.