polymer

A polymer is a large molecule (macromolecule) composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties and purposes.
Polypropylene
Polypropylene
IUPAC name Poly(propane-1,2-diyl)
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox references

Well-known examples of polymers include plastics and proteins. A simple example is polypropylene, whose repeating unit structure is shown at the right. However, polymers are not just limited to having predominantly carbon backbones, elements such as silicon form familiar materials such as silicones, examples being silly putty and waterproof plumbing sealant. The backbone of DNA is in fact based on a phosphodiester bond.

Natural polymer materials such as shellac and amber have been in use for centuries. Biopolymers such as proteins and nucleic acids play crucial roles in biological processes. A variety of other natural polymers exist, such as cellulose, which is the main constituent of wood and paper.

The list of synthetic polymers includes Bakelite, neoprene, nylon, PVC, polystyrene, polyacrylonitrile, PVB, silicone, and many more.

Polymers are studied in the fields of polymer chemistry, polymer physics, and polymer science.