Polymers

Polymers

Polymers are macromolecules made up of small repeating units of molecules. The small repeating units are called monomers. Proteins are a class of polymers which are composed of up to several thousand amino acid monomers. Carbohydrates are another class of polymers with the general formula of C_xH_2xO. Deoxyribonucleic Acid (DNA) is also a polymer. It has a molecule weight of several billion grams per mole.

There are several ways in which the monomers get together to form the polymer. We will discuss two ways:

• Addition polymerization
• Condensation polymerization

Addition polymerization

Addition polymerization occurs when the monomers are “added” together through their unsaturated bonds in order to form a polymer.

Examples include:

Vinyl chloride monomers	Added together they make polyvinyl chloride (PVC)
Propylene	Monomers are added together to yield polypropylene
Tetrafluoroethene	Monomers are added together to yield teflon

Condensation Polymerization

Condensation polymerization occurs when the monomers are brought together to form a polymer and a small molecule, such as water.

For example:

C₂H₅NO₂ + C₂H₅NO₂ → C₄H₈N₂O₃ + H₂0

(C₂H₇N₂)₂ + (C₂H₂O₄)₂ → C₈H₁₂N₄O₅ + H₂0