* The reactants must have functional groups that can react with each other to form a covalent bond. For example, a carboxylic acid group can react with an amine group to form an amide bond, or a hydroxyl group can react with a isocyanate group to form a urethane bond.
* The reaction must be carried out in a way that allows the small molecule to be removed from the reaction mixture. This can be done by heating the reaction mixture, or by using a solvent that can dissolve the small molecule.
* The reaction must be carried out in the absence of water. Water can react with the functional groups on the reactants, preventing them from reacting with each other.
Condensation polymerisation is used to produce a wide variety of polymers, including polyesters, polyamides, and polyurethanes. These polymers are used in a variety of applications, such as clothing, packaging, and construction.
