What is polymerization? Give an example of a polymerization reaction.

Polymerization is a chemical process in which small molecules called monomers join together to form a large, complex structure known as a polymer. There are two main types of polymerization: addition (chain-growth) polymerization and condensation (step-growth) polymerization.

Addition Polymerization Example:

A common example of addition polymerization is the formation of polyethylene from ethylene monomers. Here, ethylene (CH₂=CH₂) is the monomer. Through the polymerization process, the double bonds between carbon atoms in the ethylene molecules are broken and new single bonds are formed, linking the monomers into a long chain, resulting in polyethylene.

Condensation Polymerization Example:

An example of condensation polymerization is the formation of nylon-6,6 from hexamethylenediamine and adipic acid. In this reaction, the amine and carboxyl groups react, forming an amide bond and releasing water molecules. The result is the polymer nylon-6,6.