Facile Preparation of Highly Alkaline Stable Poly(arylene-imidazolium) Anion Exchange Membranes through an Ionized Monomer Strategy

The preparation of polyelectrolytes with excellent stability in high alkaline conditions still faces several challenges. In this study, we report a novel imidazolium-ionized monomer PhIM [PF6], modified by the propylbenzene group on the position of N1/N3, which can be copolymerized with 1,1,1-trifluoroacetone under superacid-catalyzed conditions. The main-chain poly(arylene-imidazolium) polymers with a controllable degree of functionalization, high molecular weight, and good solubility are successfully prepared without further postfunctionalization. Two copolymers (block-like and random) can also be prepared by introducing biphenyl as a comonomer and adjusting the feed order. Due to their different microstructures, the two copolymers exhibit different ion conduction behaviors, water absorption capacities, and mechanical properties. The obtained polymer membranes exhibit high hydroxide conductivities and high chemical stability even after treatment in a 10 M NaOH solution at 80 degrees C. In summary, we highlight a simple, effective, and low-cost strategy to prepare highly alkaline stable poly(arylene-imidazolium) polymers.

Automated summary

A novel imidazolium-ionized monomer was used to prepare poly(arylene-imidazolium) polymers with excellent stability in high alkaline conditions. The polymer membranes showed high hydroxide conductivities and chemical stability even after treatment in a 10 M NaOH solution at 80 degrees C, demonstrating a simple and cost-effective strategy for preparation.