FUNCTIONALIZATION OF CROSSLINKED POLYSTYRENE RESINS BY CHEMICAL MODIFICATION.

The functionalization of crosslinked PS has been studied extensively since the first polymeric reagent, ion exchange resins, were prepared three decades ago. Functionalized PS are now used extensively in applications as varied as ion exchange, supports for chromatography or catalysis, complexing agents for hydrometallurgy, supports or protecting groups in organic synthesis, and polymeric reagents. The reactions used in the functionalization of crosslinked PS resins, although similar to those for soluble PS, are usually more difficult to carry out due to the insolubility of the resins which make the reactions heterogeneous and often prevent simple characterization of the product by the usual methods of analysis. The following chemical reactions are described which have been used in the reported study for functionalization of crosslinked PS - halogenation (bromination and chlorination); chloromethylation; formylation; acylation and carboxylation; methylation; and phosphimization.