A polymer is a large molecule that is made up of repeating subunits connected to each other by chemical bonds. Do you need some examples of polymers? Here is a list of materials that are natural and synthetic polymers, plus some examples of materials that are not polymers at all.
Polymers are both found in nature and manufactured in laboratories. Natural polymers were used for their chemical properties long before they were understood in the chemistry laboratory: Wool, leather, and flax were processed into fibers to make clothing; animal bone was boiled down to make glues. Natural polymers include:
- Proteins, such as hair, nails, tortoiseshell
- Cellulose in paper and trees
- Starches in plants such as potatoes and maize
- Pitch (also known as bitumen or tar)
- Wool (a protein made by animals)
- Silk (a protein made by insects)
- Natural rubber and lacquer (proteins from trees)
Polymers were first manufactured by people seeking substitutes for natural ones, in particular, rubber and silk. Among the earliest were semi-synthetic polymers, which are natural polymers modified in some way. By 1820, natural rubber was modified by making it more fluid; and cellulose nitrate prepared in 1846 was used first as an explosive and then as a hard moldable material used in collars, Thomas Edison's film for movies and Hilaire de Chardonnet's artificial silk (called nitrocellulose).
Fully synthetic polymers include:
- Bakelite, the first synthetic plastic
- Neoprene (a manufactured form of rubber)
- Nylon, polyester, rayon (manufactured forms of silk)
- Polyethylene (plastic bags and storage containers)
- Polystyrene (packing peanuts and Styrofoam cups)
- Epoxy resins
- Silly putty
So while paper plates, styrofoam cups, plastic bottles, and a block of wood are all examples of polymers, there are some materials which are not polymers. Examples of materials which are not polymers include:
- Ionic compounds, such as salt
Usually, these materials form chemical bonds, but not the long chains that characterize polymers. There are exceptions. For example, graphene is a polymer made up of long carbon chains.
Resources and Further Reading
- Cowie, J.M.G. and Valeria Arrighi. "Polymers: Chemistry and Physics of Modern Materials," 3rd ed. Boca Raton, LA: CRC Press, 2007.
- Sperling, Leslie H. "Introduction to Physical Polymer Science," 4th ed. Hoboken, NJ: John Wiley & Sons, 2006.
- Young, Robert J., and Peter A. Lovell. "Introduction to Polymers," 3rd ed. Boca Raton, LA: CRC Press, Taylor & Francis Group, 2011. Print.