A layered 2D triaminoguanidine-glyoxal polymer and its transition metal complexes as novel insensitive energetic nanomaterials

A new member of the 2D carbon-nitrogen-rich family of nanomaterials was synthesized by polycondensation of triamino-guanidine hydrochloride with glyoxal. The obtained polymer (TAGP) has a carbon-to-nitrogen ratio of 3:4, identical to a ratio found in carbon nitrides. Our analysis showed that TAGP has a layered 2D network-type structure. TAGP is dispersible in polar organic solvents and forms stable complexes with various transition metal ions (TAGP-Ms). TAGP and most TAGP-Ms were found to exhibit properties of insensitive Energetic Materials (EMs), where TAGP shows a very low sensitivity to impact (I_m = 71.7 J) and to friction (>352.8 N). TAGP has also higher nitrogen content than all currently used energetic polymers, including glycidyl azide polymer [GAP], poly(3-nitrato-methyl-3-methyloxetane) [poly-NIMMO], and poly(glycidyl nitrate) [poly-GLYN]. Velocity of detonation of TAGP (6657 m s^-1) was calculated to be significantly higher than that of azide-containing GAP and comparable to that of the nitrate ester-based poly-GLYN. In our perspective, TAGP is also an example of a modular and combinatorial approach in which high nitrogen-content aminoguanidine derivatives, reacted with amine-reactive low-carbon-content or energetic crosslinkers, can produce novel energetic polymers with tuneable properties and performance. The properties of the aminoguanidine-based EPs could be even further modified and tuned by coordination of transition metal ions. Our novel TAGP and TAGP-M energetic nanomaterials have great potential to be used in solid propellants and in energetic formulations and composites as new generation energetic binders and combustion catalysts.