Lisäyspolymeroitumisen

Lisäyspolymeroituminen, also known as addition polymerization, is a chemical process where monomers join together to form long polymer chains without the elimination of any atoms or small molecules. This type of polymerization typically involves monomers containing double or triple bonds. The process often proceeds via a chain reaction mechanism, which can be initiated by free radicals, cations, or anions.

In free radical addition polymerization, an initiator molecule generates free radicals. These radicals then attack the double bond of a monomer, creating a new radical on the monomer. This process continues, adding more monomers to the growing chain. Chain termination occurs when two growing radical chains combine or when a radical abstracts an atom from another molecule.

Cationic and anionic addition polymerizations follow similar chain-growth principles but involve charged intermediates instead of radicals. Cationic polymerization is typically initiated by strong acids or Lewis acids, while anionic polymerization is initiated by strong bases or nucleophiles.

Common examples of polymers formed through addition polymerization include polyethylene, polypropylene, and polyvinyl chloride (PVC). These polymers are widely used in various applications due to their diverse properties, such as flexibility, strength, and chemical resistance. The control over molecular weight and polymer architecture can be achieved by carefully selecting the initiator, reaction conditions, and monomer concentration.