Quaternary ammonium ionene porous polymers via Menschutkin reaction of methylated polyethyleneimine and dibromoalkanes

Menschutkin reaction between methylated polyethylenimine (MePEI) and α,ω-dibromoalkane compounds in N,N-dimethylformamide (DMF) accompanied by vaporization of DMF successfully yielded network polymers, whose crosslinking points are formed by quaternary ammonium salt. The reactions with 1,4-dibromobutane (DBB) or DBH at higher reaction temperatures produced porous polymers induced by phase separation. The porous polymers were obtained by the reactions α,ω-dibromoalkane with methylene length ranged from 4 to 12 in ethyl acetate. Morphology of the porous polymers was composed by aggregated and connected particles in the order of μm and their sizes were strongly affected by the reaction temperature, methylene length of dibromoalkane, molecular weight of MePEI, and materials concentration in the reaction systems. The resulting porous polymers were thermally stable under 200 °C, and unbreakable under the compression of 50 N. The resulting porous polymers were thermally adhesive and self-healable derived from their vitrimeric features.