When monomers, which are small individual molecules, combine chemically to create a chain-like bond, it is called polymerization. Polymerization can be made from a set of monomers of the same molecule or from several types of molecules combined. However, to be categorized as a polymer, a minimum of 100 molecules of monomers combined together is required.
To initiate polymerization, whether by condensation or addition, a catalyst is needed to start the chemical reaction. Catalysts can be the increase of temperature, the increase of pressure or the emission of UV waves.
Polymerization by Condensation
The process of polymerization by condensation is a form of polymerization which is done in stages. During the stages, the monomers react with each other to create larger structural assemblies, while releasing by-products.
The by-products generated are called condensates and are usually water or methanol molecules.
Addition polymerization is essentially the same as condensation polymerization. The difference between the two is that during addition polymerization, the monomers remain intact and no by-products are produced. Also known as chain reaction polymerization, this reaction requires monomers and the presence of at least one dual bond.
Uses of Polymerization
Products of polymerization are found in many areas. To name just three, polymers can be natural, artificial or synthetic.
Polymers can be cellulose like starch or rubber. Rarer are the artificial polymers like cellulose acetate. The most common polymers are synthetic ones. Since they are loosely used in industrial and social environments, they are everywhere. We can think of polyethylene, polystyrene, silicone glues or elastomers. Of course, there are many more, but you get the idea!