Cationic polymerization is a type of chain-growth polymerization that involves the formation of positively charged ions, or cations, to initiate the reaction. This process typically occurs with monomers that have electron-rich double bonds, allowing them to react with the cations and form long polymer chains. Common examples of monomers used in this process include styrene and isobutylene. The reaction can be initiated using various methods, such as Lewis acids or protonic acids, which generate the cations needed for polymerization. Cationic polymerization is often used in the production of adhesives, coatings, and other materials due to its ability to create polymers with specific properties and high molecular weights.