The Chemistry and Physics of Plastics

Polymers are often named after the monomer rather than after the repeating unit in the structure thus the polyethylene molecule, prepared from the monomer ethylene, consists of a long chain of repeating methylene —(CH2)— groups (Formula 1). Polymers prepared from more than one species of monomer are called copolymers, e.g. butadiene-styrene polymers. 

Formula 1. Polyethylene consists of a long chain of repeating methylene groups. 

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