Functional groups are atoms or groups of atoms that provide with specific chemical properties the compounds in which they are contained.

According to the functional group of the molecule, organic substances can be classified in homologous series (such as alcohols, ketones, carboxylic acids, etc.) that show similarities in chemical behavior and physical properties, as they have the same functional group.

For example, some molecules used for binders (chemicals usually involved to increase the mechanical resistance of the ceramic material) contain functional groups capable of binding clay micelles and hard inorganic raw materials, developing a cross-linking net that increases the resistance of raw tiles after the drying process.