lisäpolymeroinnista

Lisäpolymerointi, known in English as addition polymerization, is a fundamental chemical process in polymer science. It involves the sequential addition of monomers to a growing polymer chain without the loss of any atoms. This means that the empirical formula of the repeating unit in the polymer is the same as that of the monomer.

The process typically begins with an initiator molecule that forms a reactive intermediate, such as a free radical, a carbocation, or a carbanion. This reactive intermediate then attacks the double or triple bond of a monomer, forming a new, larger reactive intermediate. This chain reaction continues as more monomers add to the growing chain. The process stops when the reactive chain ends are quenched by reacting with other growing chains, impurities, or specific terminating agents.

Common examples of monomers that undergo addition polymerization include alkenes like ethylene, propylene, and styrene. These reactions yield important polymers such as polyethylene, polypropylene, and polystyrene, respectively. Addition polymerization can be carried out via several mechanisms, including free radical polymerization, cationic polymerization, and anionic polymerization, each differing in the nature of the reactive intermediate. The control over molecular weight and polymer architecture can vary significantly depending on the chosen mechanism and reaction conditions. This method is widely used for the industrial production of many common plastics and synthetic rubbers due to its simplicity and efficiency.