Pendant group

{{short description|Group of atoms attached to a long molecule's backbone chain}}

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Side-group
An offshoot, neither oligomeric nor polymeric, from a chain.{{cite journal|title=Glossary of basic terms in polymer science (IUPAC Recommendations 1996)|journal=Pure and Applied Chemistry|year=1996|volume=68|issue=12|pages=2287–2311|doi=10.1351/pac199668122287|doi-access=free| last1=Jenkins | first1=A. D. | last2=Kratochvíl | first2=P. | last3=Stepto | first3=R. F. T. | last4=Suter | first4=U. W. }}

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In IUPAC nomenclature of chemistry, a pendant group (sometimes spelled pendent) or side group is a group of atoms attached to a backbone chain of a long molecule, usually a polymer. Pendant groups are different from pendant chains, as they are neither oligomeric nor polymeric.{{GoldBookRef|title=pendant group (side group)|file=P04472}}

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For example, the phenyl groups are the pendant groups on a polystyrene chain.

Large, bulky pendant groups such as adamantyl usually raise the glass transition temperature ({{mvar|T{{sub|g}}}}) of a polymer by preventing the chains from sliding past each other easily. Short alkyl pendant groups may lower the {{mvar|T{{sub|g}}}} by a lubricant effect.