Towards investigating the characteristics and thermal kinetic behavior of emergent nanostructured nitrocellulose prepared using various sulfonitric media

With the aim of developing promising generation of cellulose-based energetic materials, nanostructured nitrocellulose biopolymers (NNCs) were prepared from cellulose microcrystals using different sulfonitric media. Their molecular structure, physicochemical features, crystallinity and thermal behavior were examined to scrutinize the nitration processes by pointing out the effect of nitric acid content in the nitrating medium. The experimental findings showed that the produced NNCs displayed outstanding properties, including elevated density (≥ 1.689) and great substitution degree (≥ 2.58), which are higher than those of the conventionally used pristine nitrocellulose (NC). Furthermore, it was found that the increase of nitric acid concentration from 70 to 100% promoted the nitrogen content, density and viscosity-average molecular weight of the as-prepared NNCs, whereas, their crystallinity index and thermal stability decreased. Their non-isothermal decomposition kinetics were also investigated using isoconversional approaches, revealing a decreased trend of the Arrhenius parameters from NNC-70 to NNC-100, and hence following different decomposition models. Consequently, these results enrich future prospects for the design of new generation of energetic nanostructured cellulosic biopolymers for potential use in advanced composite explosives and solid propellants.