Nanostructured electrospun nitrocellulose: Stabilization mechanisms and degradation kinetics of organic stabilizers

Nitrocellulose (NC) is extensively utilized in military applications. However, its pronounced hygroscopicity and high specific surface area render it susceptible to thermal instability, posing a latent risk of spontaneous combustion. Conventional stabilization strategies involve the incorporation of organic stabilizers to enhance thermal stability, yet these are often hampered by non-uniform stabilizer dispersion. Electrospinning technology offers an effective solution by enabling the homogeneous dispersion of stabilizers at the nanoscale, thereby significantly improving their distribution within NC fibers. In this study, nanostructured NC was fabricated via electrospinning, and two organic stabilizers—N-methyl-p-nitroaniline (MNA) and 3-methyl-1,1-diphenylurea (AKII)—were introduced to synthesize nanocomposite nitrocellulose. The morphological characteristics of the resulting samples were investigated using focused ion beam scanning electron microscopy (FIB-SEM) to assess the influence of stabilizers on fiber morphology. The thermal stability and pyrolysis mechanisms were systematically examined through thermogravimetric analysis coupled with differential scanning calorimetry (TG-DSC) and Fourier-transform infrared spectroscopy (FTIR) conducted at multiple heating rates, and the effects of the two stabilizers on the thermal properties of NC were evaluated. A comprehensive kinetic analysis was performed using various model-free methods to elucidate the relationship between activation energy and conversion rate. The most probable mechanistic functions for the thermal decomposition of each sample were determined using master plots, followed by refinement of the kinetic models. The results indicate that AKII exhibits superior stabilizing efficacy compared to MNA.