A polymer is a macro molecule with a high molecular weight. It consists on a long chain that can present many branches.

The structure is formed by many basic units: these are single molecules, monomers, that can be described as pearls of a pearl necklace.

They may be aggregated in groups of two, three, four ….up to hundreds (high polymers).

Every monomer is linked to the others thanks to a chemical bonding: the polymer can be polymerised using solvents able to break the chains.