Polymer

A polymer is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. The word is derived from the Greek, πολυ, polu, "many"; and μέρος, meros, "part". Well known examples of polymers include plastics, DNA and proteins. A simple example is polypropylene whose repeating unit structure is shown at right.
Polypropylene

IUPAC name
poly(1-methylethylene)
Except where noted otherwise, data are given formaterials in their standard state(at 25 °C, 100 kPa)Infobox disclaimer and references
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. Natural polymer materials such as shellac and amber have been in use for centuries. Biopolymers such as proteins (for example hair, skin and part of the bone structure) 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. Typical synthetic polymers are Bakelite, neoprene, nylon, PVC (polyvinyl chloride), polystyrene, polyacrylonitrile and PVB (polyvinyl butyral). Polymers are studied in the fields of polymer chemistry and polymer science