Structural Control of Energetic Triaminoguanidine Nitrate Polymer Nanostructures for Reduced Thermal Reactivity

A group of 2D nitrogen-rich nanopolymers has been synthesized by the cross-linking reaction of triaminoguanidine nitrate (TAGN) with glyoxal at various designated experimental conditions. These nanopolymers could be used as ligands of insensitive energetic complexes as well as the desensitizing agents of nitramines. It is quite important to investigate the structural dependence of this material on its thermal reactivity. The results showed that the obtained polymer so-called TAGP has a nanolayered 2D network-type structure with a diameter of roughly 10 nm scale defects. In particular, the TAGP samples with a higher molecular weight could be obtained by increasing the reaction temperature and the TAGN concentration. It is worth noting that the nitramine crystals constrained with TAGP layers with higher molecular weight have a higher energy density. Significantly, the control of activation energy (E_a) and kinetic models for TAGP samples can be achieved by adjusting the reaction conditions. The E_a of the resulting TAGP samples decreases with the increase in their cross-linking concentration. Specifically, the TAGP obtained from the TAGN/DMSO solution with the lowest concentration exhibits the highest E_a value of 134.1 kJ·mol^-1, which corresponds to the F1 decomposition model. Conversely, the TAGP obtained from the highest concentration has a significantly lower E_a value of only 81.0 kJ·mol^-1, following an A2 model. The TAGP samples with intermediate concentrations conform to the random chain scission (L2) model.