A new poly(organophosphazenes) copolymer was formed from the reaction of aminopentafluoroethoxycyclotriphosphazene, sodium phenoxide, and poly(dichlorophosphazene). The polymer was thermoplastic and the Tgincreased with an increasing amount of the phenol group. The Tgof the polymer with aminopentafluoroethoxycyclotriphosphazene attached as a pendant group was similar to the Tgof polyfluoroethoxyphosphazene.