polymeriseringsreaksjon

Polymeriseringsreaksjon is the chemical process by which relatively small molecules, known as monomers, combine chemically to produce a long chain-like molecule, a polymer. This reaction involves the formation of new covalent bonds between the monomer units, effectively linking them together. The repeating structural unit of the polymer is derived from the monomer.

There are two primary mechanisms for polymerization: chain-growth polymerization and step-growth polymerization. Chain-growth polymerization, also known as addition polymerization, involves monomers adding sequentially to an active center. This typically proceeds through a chain initiation, propagation, and termination sequence. Examples include the polymerization of alkenes like ethene to form polyethylene. Step-growth polymerization, also known as condensation polymerization, involves monomers reacting with each other to form dimers, trimers, and then longer chains. Often, a small molecule, such as water, is eliminated as a byproduct during the reaction. Polyesters and polyamides are common examples of polymers formed by step-growth polymerization.

The properties of the resulting polymer are heavily dependent on the type of monomer used, the reaction conditions, and the polymerization mechanism. Factors such as molecular weight, branching, and tacticity (the stereochemical arrangement of monomer units) influence the polymer's physical and chemical characteristics, determining its suitability for various applications, ranging from plastics and fibers to adhesives and coatings.