Pendant group

A pendant group or side group is a group of molecules attached to a backbone chain of a long molecule. Usually, this molecule would be a polymer.

File:Polystyrene formation.PNG

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 (T_g) of a polymer by preventing the chains from sliding past each other easily. Short alkyl pendant groups may lower the T_g by a lubricant effect.