Thirty-minute preparation of microporous polyimides with large surface areas for ammonia adsorption†
Abstract
Toxic solvents and catalysts, tedious monomer synthesis, and long reaction time significantly limit the sustainable and large-scale preparation and practical application of microporous polyimides (MPIs). In this work, three kinds of MPIs were successfully prepared through thermal polycondensation in the diphenyl sulfone (DPS) solvent using 1,4,5,8-naphthalenetetracarboxylic dianhydride and triamines as building blocks. The polymerization can be completed in 30 min, and the resultant MPIs exhibit large surface areas up to 1825 m2 gā1. Owing to their abundant microporous structures and plenty of imide rings, MPIs demonstrate excellent ammonia adsorption performance (21.10 wt%, at 303 K and 1.0 bar) and favorable regeneration ability. DPS as a non-volatile solvent can be recovered and recycled three times. In comparison with previous reports, this strategy is more time efficient, environmentally friendly and potentially scalable.