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In this research, three distinct ternary-nanothermites were subsequently integrated into double base propellant formulated with nitrocellulose (NC) and diethylene glycol dinitrate (DEGDN). These nanothermites consisted of magnesium and aluminum alloy (MgAl) as fuel and metal oxides (CuO, NiO, and TiO2) acting as oxidizers. Experimental results demonstrated the uniform distribution of the three investigated nanothermites throughout the NC/DEGDN composite. DSC findings indicated a significant increase in the overall heat release of the NC/DEGDN double base propellant upon the addition of the three nanothermites. It is found that the type of oxidizer within the nanothermite composition played a crucial role in the thermo-kinetic proprieties of the NC/DEGDN propellant. Specifically, nanothermites incorporating CuO and TiO2 acted as catalysts, substantially enhancing the thermolysis of the propellant. In contrast, MgAl–NiO exhibited a stabilizing effect on the thermal decomposition of NC/DEGDN propellant. These findings offer appreciated insights into the tailoring properties of double-base propellant by selectively incorporating specific nanothermites based on their oxidizer content. [ABSTRACT FROM AUTHOR]

This study aims to elucidate the potential effect of encapsulated nanothermite on the characteristics and thermo-kinetic features of double base NC/DEGDN propellant. Nitrocellulose was used as a coating material to encapsulate the MgAl–CuO nanothermite, creating a core–shell structure. The prepared energetic formulations were subjected to thorough characterization using various techniques, including Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetry analysis, calvet calorimeter analyses, and differential scanning calorimetry (DSC). Experimental results confirmed the uniform distribution of the nitrocellulose-encapsulated MgAl–CuO (NC@MgAl–CuO) particles within the NC/DEGDN matrix. DSC findings highlighted that the addition of NC@MgAl–CuO nanothermite significantly increased the total heat release of the NC/DEGDN propellant from 3787 to 4175 J/g. The kinetic parameters associated with the thermal decomposition of the developed energetic formulations were also predicted using isoconversional kinetic methods, including (TAS, it-KAS, and VYA). Thermokinetic findings demonstrated the notable impact of MgAl–CuO particles coated with NC on the reactivity and catalytic behavior of NC/DEGDN propellant. Specifically, the Arrhenius parameters of NC/DEGDN formulation is decreased by 32% when the NC@MgAl–CuO nanothermite was introduced. Overall, this study serves as a valuable reference for future research focused on the investigation of coated metastable intermolecular composites and their effects on the reactivity and combustion features of solid propellants. [ABSTRACT FROM AUTHOR]

To explore polysaccharides for developing energetic biopolymers, a promising energy-rich nitrochitosan (NCS) was successfully prepared through electrophilic nitration of chitosan. The chemical structure and morphology of the synthesized NCS and its precursor were confirmed by infrared spectroscopy, elemental analysis, and scanning electron microscopy. The energetic performance, thermal behavior, and degradation kinetics of NCS were also evaluated. The results showed that the designed nitrogen-rich ( N c = 16.79%) NCS presents excellent energetic features, such as a calorific value of 10,573 J/g, a density of 1.708 g/cm3, an impact sensitivity of 15 J, and a detonation velocity of 7788 m/s, which are markedly better than those of NC and GAP. Meanwhile, the thermal investigation based on deconvoluted non-isothermal DSC experiments combined with isoconversional kinetic methods indicated that NCS displays two consecutive exothermic decomposition events within the temperature range of 133–180 °C and 185–240 °C, and exhibits apparent activation energies of 74 kJ/mol and 152 kJ/mol, respectively, which are lower than the common thermolysis energy range of NC (140–190 kJ/mol), demonstrating the improved reactivity of the aforementioned energetic NCS. Overall, this study established that NCS could serve as an outstanding energetic polysaccharide for potential application in high-performance composite explosives and solid rocket propellants. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]