Synthesis and ion-coupling reactions of telechelic polystyrene having cyclic onium salt groups

A series of mono- and bifunctional polystyrenes (1c and 1'c) having 1-methylpyrrolidinium salt end groups were prepared through sequential derivatization, i. e., tosylation and quaternization reactions, of prepolymers having 3-hydroxypropyl groups (1a and 1'a) produced by end-capping reactions of the relevant living polymers. The 1-methylpyrrolidinium salt end group was found to undergo a selective ring-opening reaction at 100 degrees C by nucleophilic attack of a benzoate counter anion introduced by ion-exchange reaction. The ion-coupling reaction of 1c and 1'c with poly(styrene-co-acrylate salt) was found to take place upon coprecipitation of an equimolar mixture into methanol to afford ionically Linked pseudo-graft and network products, respectively. The subsequent heat treatment, converting the ionic bond into a covalent one, results in branched and crosslinked polystyrene with predetermined structural parameters.