What are Polymers?

Did you know that polymers are in countless different household objects that are used every day? The term “polymer” is very vague, however – it can refer to one of many different substances and can come in countless different shapes, sizes, colors and textures. However, most chemists can agree that a polymer can be defined as a chemical composed of a series of repeating units. Some are natural such as wool, silk and proteins, while others are artificial such as nylon and polyester.

Polymers are generated through a process called polymerization, where smaller molecules called monomers chemically combine to form a larger network of molecules. This larger network needs to include at least one hundred monomer molecules in order to be considered a polymer. There are two different types of polymerization processes: condensation polymerization, where each step of polymerization is joined by the formation of a simple molecule (i.e. water), and addition polymerization, which uses catalysts that can have a major influence on the chemical properties of the polymer.

Plastics are one of the most well-known examples of polymers. They come in two forms: thermoplastics and thermosets.  Thermoplastics (like polyethylene blades) will melt when applied with heat, and then harden as they cool. They can be melted and remelted for reuse. Thermosets (like polyurethane blades) include molecules that are linked as they are heated which is a curing process.  Once this reaction takes place they cannot be melted and reused again.