Abstract: The application discloses a process for making a polymer having pendant side groups comprising: (i) polymerising an olefinically unsaturated monomer functionalized with (a) an azide group optionally protected by a protecting group, or (b) an alkyne group optionally protected by a protecting group, by living radical polymerization, most preferably RAFT, transitional metal mediated living radical polymerization (TMM-LRP) and/or atom transfer radical polymerization, to produce a polymer intermediate; (ii) removing, when present, at least a portion of the total number of protecting groups from the polymer intermediate; (iii) reacting the polymer intermediate with at least one pendant side group moiety functionalised with (a) an alkyne group or (b) an azide group respectively so that the alkyne and azide groups react to attach the pendant side group to the polymer. Processes for making supports comprising pendant side groups, and polymers and supports prepared by the method are also disclosed.