Polümerisatsioonitüüp

Polümerisatsioonitüüp refers to the classification of polymerization reactions based on their reaction mechanisms. There are two primary types of polymerization: addition polymerization and condensation polymerization.

Addition polymerization involves the joining of monomers without the loss of any atoms. The monomers add to one another in such a way that the resulting polymer contains all the atoms of the original monomers. This type of polymerization typically proceeds through a chain reaction mechanism, which can be initiated by free radicals, cations, or anions. Common examples of polymers formed by addition polymerization include polyethylene, polypropylene, and polyvinyl chloride (PVC). The molecular weight of the polymer increases stepwise as monomers are added to a growing chain.

Condensation polymerization, on the other hand, involves the reaction between monomers with the simultaneous elimination of a small molecule, such as water, methanol, or hydrochloric acid. In this process, functional groups on the monomers react to form new covalent bonds, and the byproduct molecule is released. The resulting polymer's repeating unit contains fewer atoms than the sum of the atoms in the reacting monomers. Examples of condensation polymers include polyesters, polyamides (like nylon), and polycarbonates. This type of polymerization often proceeds by a step-growth mechanism, where monomers react to form dimers, then trimers, and so on, until high molecular weight polymers are formed.