Radikaalpolümerisatsiooniks

Radikaalpolümerisatsiooniks is a Finnish term referring to radical polymerization. This is a type of chain-growth polymerization process where monomers react with each other in the presence of a radical initiator. The process involves three key stages: initiation, propagation, and termination.

Initiation begins with the homolytic cleavage of a radical initiator, typically by heat or light, to form reactive free radicals. These radicals then attack the double bond of a monomer molecule, creating a new monomer radical. Propagation is the chain-lengthening step where the monomer radical adds to successive monomer units, extending the polymer chain. This process continues rapidly, forming long polymer chains.

Termination occurs when the growing radical chains are deactivated. This can happen through various mechanisms, such as combination (two radical chains joining together) or disproportionation (one radical chain transferring a hydrogen atom to another, forming a saturated and an unsaturated chain end). The type of termination can influence the molecular weight and architecture of the resulting polymer.

Radical polymerization is a widely used technique for producing a vast array of polymers, including polyethylene, polystyrene, and polyvinyl chloride, due to its versatility and ability to polymerize a broad range of monomers. It can be carried out in different conditions, such as bulk, solution, suspension, or emulsion polymerization, each offering specific advantages for controlling the reaction and the properties of the final polymer.