additiopolymerisaatiota

Additiopolymerisaatio, also known as addition polymerization, is a fundamental chemical process where monomers, small molecules containing reactive double or triple bonds, link together to form long polymer chains. Unlike condensation polymerization, no byproducts like water or methanol are released during this reaction. The key characteristic of addition polymerization is that the monomer units add to one another sequentially, with the double or triple bonds in the monomers opening up to form single bonds, thus creating the repeating units of the polymer.

This process typically proceeds via a chain reaction mechanism, which involves three distinct stages: initiation, propagation, and termination. Initiation is the step where an active center, often a free radical, anion, or cation, is generated, which then attacks a monomer molecule. This creates a reactive monomer species. Propagation is the longest phase, where the reactive monomer species repeatedly adds more monomer units to the growing polymer chain. Finally, termination occurs when the active center is deactivated, effectively stopping the chain growth. This can happen through various mechanisms, such as combination of two growing chains or disproportionation.

Common examples of polymers formed through addition polymerization include polyethylene, polypropylene, and polyvinyl chloride (PVC). These materials are ubiquitous in modern life, finding applications in packaging, construction, textiles, and countless other industries due to their diverse properties, which can be tailored by controlling factors like monomer choice, reaction conditions, and molecular weight.