4. Polymer Families and Their Extended Activities

The term polymer (many monomers) is derived from the ancient Greek word πολύζ (polus, meaning many, much) and μέροζ (meros, meaning parts), and refers to a molecule whose structure is composed of multiple repeating units of carbon, mostly hydrogen and/or nitrogen and oxygen (Figs. 4.1, 4.2 and 4.8). Indeed, the term polymer was first introduced in 1833 by the Swedish chemist, Jons Jakob Berzelius. He also introduced the term isomer (from the Greek isos meaning equal, and meros meaning part) to describe substances having identical compositions but differing properties. In 1922, the German chemist, Herman Staudinger, felt it necessary to coin the word macromolecule to describe large covalently bonded organic chain molecule containing more than 10³ atoms. A macromolecule is a very large molecule commonly created by polymerization of smaller subunits, monomers. The most common macromolecule in biochemistry is biopolymers (nucleic acids, proteins, etc.). According to IUPAC (International Union of Pure and Applied Chemistry) definition, the term macromolecule as used in polymer science refers only to a single molecule.