Carboxy end-capped polybutadine and butadine-acrylonitrile copolymer were transformed into dicationically living poly (THF-b-butadine-b-THF) and poly (THF-butadine-avryloni-trile-b-THF) triblock chains

respectively

through the ring-opening polymerization of THF. By terminating the reaction with liquid ammonia or diethylamine the telechelic triblock with primary or tertiarr amine end-groups

respectively

was synthesized. The tertiary amine terminated triblock oligomer reacted with a

a'-dic

hloro-p-xylene gives rise to the formation of thermo-plastic elastomer ionene polymer.