branch (side chain, pendant chain)

Also contains definitions of: long-chain branch, short-chain branch

in polymers
An oligomeric or polymeric offshoot from a macromolecular chain.
  1. An oligomeric branch may be termed a short-chain branch.
  2. A polymeric branch may be termed a long-chain branch.
PAC, 1996, 68, 2287 (Glossary of basic terms in polymer science (IUPAC Recommendations 1996)) on page 2297