Effect of functional group on thermal stability of cellulose derivative energetic polymers

This paper describes thermochemical properties and decomposition characteristics of cellulose acetate nitrate, azidodeoxy cellulose and azidodeoxy cellulose nitrate as three cellulose derivatives which are proper candidates for usage as novel binders in propellant compositions. Differential thermal analysis (DTA), differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques have been employed to elucidate the reaction process of these energetic polymers. The results of the experiments showed that azidodeoxy cellulose nitrate decomposes exothermally during three continuous steps at temperature range of 180–500 °C. Also, azidodeoxy cellulose polymer decomposes exothermally at about 206 °C in a single step. However, cellulose acetate nitrate decomposition occurs exothermally in a single step at about 208 °C. Furthermore, the effect of DSC heating rate on the thermal decomposition of interested energetic polymers was investigated. The apparent activation energy (E), ΔG#, ΔH# and ΔS# of the decomposition processes were obtained from the non-isothermal DSC experiments. Based on these thermokinetic data, the relative thermal stability of investigated energetic polymers was found to obey the following order: azidodeoxy cellulose > cellulose acetate nitrate > azidodeoxy cellulose nitrate.