Pb-TKX-50燃烧催化剂的合成及热分解性能

以二氯乙二肟、二甲基甲酰胺、叠氮化钠、盐酸羟胺和硝酸铅等为原料,合成了1,1-二羟基-5,5′-联四唑羟胺铅盐(Pb-TKX-50)燃烧催化剂,研究了Pb-TKX-50对推进剂机械感度的影响以及与推进剂组分的相容性;利用差示扫描量热法和热重法研究了Pb-TKX-50在不同升温速率下的热分解过程,计算其表观活化能(E K和E O)和指前因子(A K),得到其热分解动力学参数、热分解机理函数、热爆炸温度和热力学性质。结果表明,在推进剂配方中加入Pb-TKX-50燃烧催化剂,可以改善其撞击感度和摩擦感度,且与推进剂组分的相容性良好;Pb-TKX-50的主峰分解温度相对于TKX-50的主峰分解温度显著提高,说明其热稳定性显著提高。Ozawa法和Kissinger法得到Pb-TKX-50的表观活化能分别为181.45 kJ/mol和182.49 kJ/mol,且热分解过程符合Avrami-Erofeev方程;Pb-TKX-50的自加速分解温度和爆炸临界温度分别为500.53 K和544.33 K,表明其热稳定性良好;Pb-TKX-50催化剂的热分解自由能(ΔG^≠)为158.87 kJ/mol,活化焓(ΔH^≠)为187.03 kJ/mol,活化熵(ΔS≠)为52.98 kJ/mol。

Synthesis and Thermal Decomposition Properties of Pb-TKX-50 Combustion Catalyst

The combustion catalyst Pb-TKX-50 was synthesized by using dichloroethylene dioxime,dimethylformamide,sodium azide,hydroxylamine hydrochloride and lead nitrate as raw materials and the effects of Pb-TKX-50 on the mechanical sensitivities of propellants and its compatibilities with the main components of double-base(DB)propellants were evaluated.The thermal decomposition processes of Pb-TKX-50 at different heating rates were investigated by differential scanning calorimetry and thermogravimetry,and the apparent activation energies(E K and E O)and pre-exponential factors(A K)were calculated by Ozawa and Kissinger methods.In addition,the kinetic parameters of its thermal decomposition,including mechanism function,thermal explosion temperature and thermodynamic properties,were also obtained.The results show that,the addition of Pb-TKX-50,which possesses good compatibility with the main components of DB propellants,can decrease the impact sensitivity and friction sensitivity of propellant.The peak temperature of the main decomposition stage of Pb-TKX-50 is evidently higher than that of TKX-50,indicating its higher thermal stability.The apparent activation energies of Pb-TKX-50 calculated by the Ozawa and Kissinger methods are 181.45 kJ/mol and 182.49 kJ/mol,respectively,and the thermal decomposition process fits well with the Avrami-Erofeev equation.Furthermore,the self-accelerating decomposition temperature and the explosion critical temperature of Pb-TKX-50 are 500.53 K and 544.33 K,respectively.The free energy(ΔG^≠),activation enthalpy(ΔH^≠)and activation entropy(ΔS^≠)of Pb-TKX-50 decomposition are 158.87,187.03 and 52.98 kJ/mol,respectively.