What type of reaction converts alkenes into polymers?

The conversion of alkenes into polymers occurs through addition polymerization. This process involves the breaking of the double bonds in alkenes, allowing the monomers to link together to form long chains, or polymers. During addition polymerization, the reactive double bonds open up and connect with the open bonds of adjacent alkene molecules, resulting in a polymer that retains the molecular structure of the original monomer.

Addition polymerization is particularly relevant for compounds such as ethene, which can form polyethylene, a widely used plastic. The reaction proceeds with the elimination of small molecules or functional groups, distinguishing it from other types of polymerization processes. This characteristic is central to the formation of large, stable structures from relatively simple alkene molecules.

Other processes like dehydration and condensation polymerization involve the removal of water or another small molecule during the polymerization process, which is not typical for the reaction mechanism of alkenes. Substitution reactions refer to a process where one atom or group in a molecule is replaced by another, which is not applicable in the context of polymerizing alkenes.