A new poly(oxyphenylene) derivative containing a 3-(trialkylammonio)propyl substituent was synthesized via hydroiodinated poly(oxy-2-allyl-6-methyl-1,4-phenylene) followed by quaternization with trialkylamine. Poly(oxy-2-allyl-6-methyl-1,4-phenylene) obtained by oxidative polymerization of 2-allyl-6-methylphenol was allowed to read with bis(cyclopentadienyl)zirconium chloride hydride (ZrCp(2)-HCl) at room temperature in inert atmosphere in which the allyl group was converted to a terminally zirconocene-substituted propyl group. The activated propyl group can react with It to yield the 3-iodopropyl group. The quaternization of the resulting polymer was performed through the Menshutkin reaction with a series of trialkylamines to obtain the poly[oxy-2-[3-(trialkylammonio)propyl]-0-methyl-1,4-phenylene iodide]. The resulting polyammonium salt as an ion exchange resin exhibits higher thermal stability than poly[oxy-2-[(trimethylammonio)methyl]-6-methyl-1,4-phenylene salt], e.g., no decomposition in water below 100 degrees C for 24 h.