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

A series of mono‐ and bifunctional polystyrenes ( 1 c 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 ( 1 a 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°C by nucleophilic attack of a benzoate counter anion introduced by ion‐exchange reaction. The ion‐coupling reaction of 1 c 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.