What is condensation polymerisation?

Condensation polymerisation is a specific type of polymerisation process where monomers that each possess at least two functional groups react together to form a polymer, accompanied by the release of small molecules, commonly water or methanol. This occurs when the functional groups react and bond, thereby linking the monomers into long chains, while the small molecule is eliminated as a byproduct of the reaction.

This mechanism is fundamental in the formation of various types of polymers, such as polyesters and polyamides. For instance, when a carboxylic acid reacts with an alcohol, an ester linkage is formed, and water is released in the process, exemplifying condensation polymerisation.

Other options address different concepts. One incorrectly specifies that the process forms esters exclusively through heating, which is not specific to condensation polymerisation. Another suggests a reaction releasing hydrogen gas, which does not characterize the process at hand, as the focus is on the loss of small molecules like water. Lastly, the mention of breaking down polymers by adding water pertains to hydrolysis, not polymerisation, framing it within an entirely different chemical process. Thus, the chosen definition accurately encapsulates the essence of condensation polymerisation.