柠檬酸镧催化双基推进剂的非等温热分解反应动力学

采用TG-DTG和DSC技术研究了含二缩三乙二醇二硝酸酯(TEGDN)和硝化甘油(NG)的混合酯、硝化棉(NC)和用作燃烧催化剂的柠檬酸镧组成的双基推进剂在常压和流动态氮气气氛下的非等温热分解反应动力学. 结果表明, 该双基推进剂的热分解过程存在2个失重阶段: 第I失重阶段为混合酯的挥发分解过程; 第II失重阶段为主放热分解反应, 机理服从三级化学反应, 减速型α-t曲线, 动力学参数: Ea=231.14 kJ·mol-1, A=10^23.29 s-1, 动力学方程为dα/dt=10^22.99(1-α)³ e^-2.78×104/T. 由外推起始点温度(Te)和峰顶温度(Tp)计算得出该双基推进剂的热爆炸临界温度值分别为Tbe=463.62 K, Tbp=477.88 K. 反应的活化熵(⊿S^≠)、活化焓(⊿H^≠)和活化能(⊿G^≠)分别为219.75 J·mol-1·K-1, 239.23 kJ·mol-1和135.96 kJ·mol-1.

Nonisothermal Thermal Decomposition Reaction Kinetics of Double-base Propellant Catalyzed with Lanthanum Citrate

The decomposition reaction kinetics of the double-base (DB) rocket propellant composed of the mixed ester of triethyleneglycol dinitrate (TEGDN) and nitroglycerin (NG), and nitrocellulose (NC) with lanthanum citrate as a combustion catalyst was investigated by thermogravimetry and differential thermogravimetry (TG-DTG), and differential scanning calorimetry (DSC) under atmospheric pressure and flowing nitrogen gas conditions. The results showed that the thermal decomposition processes of DB propellant had two mass loss stages: volatilization and decomposition of the mixed ester in the first-stage and exothermic decomposition reaction in the second-stage. The exothermic decomposition reaction mechanism obeyed the third-order chemical reaction rule. The kinetic parameters The critical temperatures of the thermal explosion of the DB propellant obtained from the onset temperature (Te) and the peak temperature (Tp) were: Tbe=463.62 K, Tbp=477.88 K. The entropy of activation (ΔS≠), enthalpy of activation (ΔH≠), and free energy of activation (ΔG≠) of the reaction were 219.75 J·mol-1·K-1, 239.23 kJ·mol-1, and 135.96 kJ·mol-1, respectively.