Condensation polymers, including popular materials like nylon and cellulose, are formed through a reaction between monomers that have reactive functional groups on both ends. These functional groups can be carboxyl, hydroxyl, or others. Whenever two monomers react, a small molecule is released (commonly water or HCl). This process forms a new linkage between the monomers and gradually leads to a long chain of molecules, known as a polymer.

Esterification is an essential example of condensation polymerization. It involves a condensation reaction between an alcohol and a carboxylic acid. During this reaction, the hydroxyl group (-OH) from the alcohol and the carboxyl group (-COOH) from the acid react to form an ester linkage (-COO-). Simultaneously, a water molecule is released. This process is called esterification.

• Here's the chemical equation for esterification:
• Alcohol + Carboxylic Acid -> Ester + Water

Examples

• Imagine that alcohol is like a cup of milk and a carboxylic acid is like a cup of coffee. When you combine milk and coffee, you get a latte and a bit of steam (water) as a by-product. Similarly, when an alcohol and a carboxylic acid react, you get an ester and a water molecule.

• Polyester fabric is an everyday example of a polymer made through condensation polymerization. Polyester is created when a diol (a molecule with two alcohol functional groups) reacts with a dicarboxylic acid (a molecule with two carboxylic acid functional groups). The resulting polymer, polyester, is a material commonly used for making clothes, bedsheets, and other textiles.