Main-chain Polyimidazolium Polymers by One-pot Synthesis and Application as Nitrogen-doped Carbon Precursors

This paper reports on the one-pot synthesis of main-chain imidazolium-containing polymers, some of which show unusually high thermal stability. The imidazolium polymers were obtained by modified Debus-Radziszewski reactions for the chain build-up from simple organic compounds, here pyruvaldehyde, formaldehyde, acetic acid, and a variety of diamines. The reactions were performed in aqueous media at ambient conditions, being synthetically elegant, convenient and highly efficient. Finally, a simple anion-metathesis reaction was conducted to replace the acetate anion with dicyanamide, and the thermal properties of the main-chain polyimidazoliums before and after anion exchange were studied in detail, which demonstrated chain cross-linking by the counterion and a coupled unusually high carbonization yield of up to 66 wt% at 900 oC.