Porous organic polymers containing Tröger's base for enhanced NOx adsorption

The safe long-term storage of nitrocellulose (NC) has become increasingly challenging under extreme environmental conditions due to accelerated NO x release, which promotes self-catalytic decomposition of NC. In this study, Tröger’s base (TB) was integrated into porous organic polymers (POPs) to achieve dual functionality: efficient physical adsorption and stable in-situ chemical fixation of NO x within confined pore spaces. Solid-state CP/MAS 13 C NMR spectroscopy and quantum chemical calculations were employed to confirm that NO x immobilization occurs preferentially at the ortho positions of tertiary amine moieties on aromatic rings. Among the synthesized materials, the polymer resulting from the Trögerization of the Tetrakis (4-aminophenyl) methane (TAPM-TB) was identified as the optimal adsorbent, characterized by accessible ortho-active sites, a microporous structure, and an exceptional NO x uptake capacity of 3.31 mmol/g under standard conditions. Furthermore, TAPM-TB was demonstrated to extend the stability time of NC by 3.23 times in methyl violet tests. These findings highlight a novel strategy for designing materials capable of simultaneous physical adsorption and stable chemical immobilization of NO x or other gases.