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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Polymer

A very large molecule (a macromolecule) built from many repeat units linked in a chain, often thousands to hundreds of thousands of them. Polymers form by addition or by condensation of small monomer molecules.

Polymer chain and repeat unitMany ethene monomers (CH₂=CH₂) join into a long polyethylene chain. The repeat unit, –CH₂–CH₂–, is shown in brackets with subscript n for the number of repeats.n CH₂=CH₂ → –[CH₂–CH₂]ₙ–monomer → polymernrepeat unit……each vertex is a CH₂ carbon; n is often 10³–10⁵

Monomers join into a chain; the bracketed repeat unit occurs nn times.

Example

A polystyrene chain of molar mass 1.04×1051.04 \times 10^5 g/mol, with repeat unit CX8HX8\ce{C8H8} (104.15 g/mol), contains about 1000 repeat units.

See alsoMonomerRepeat unitAddition polymerCondensation polymer