DFTNAN/DNTF二元相图及低共熔物熔融动力学研究

Binary Phase Diagrams and Eutectic Melting Kinetics of DFTNAN/DNTF

通过测定3,5-二氟-2,4,6-三硝基苯甲醚(DFTNAN)/3,4-二硝基呋咱基氧化呋咱(DNTF)二元混合体系熔融过程的差示扫描量热(DSC)特征量数据,建立了T-X和H-X二元相图,并获得了该混合体系低共熔物的组成和熔点。然后,研究了低共熔物以及熔点为80℃时混合物的黏度、机械感度和理论爆炸性能。分析了不同的升温速率和添加剂对低共熔物熔融过程的影响,并通过Satava-Sesták、Coats-Redfern和通用积分方程获得了低共熔物熔融过程的动力学参数E_(a)、A和最概然机理函数。结果表明,由T-X相图和H-X相图计算得到的DFTNAN/DNTF低共熔物的组成m(DFTNAN)m(DNTF)分别为62.9437.06和62.8837.12,低共熔温度为63.84℃。调节DFTNAN和DNTF的比例,可使混合体系既达到熔铸工艺要求的工艺温度(≥80℃),又能保持较高的能量水平和较低的感度。随着升温速率的提高,熔融反应起始温度和峰温发生相应的延后;添加HMX或RDX后,熔融起始温度发生较明显的后移;DFTNAN/DNTF低共熔物的熔融动力学参数E_(a)和lg A分别为32.95 kJ/mol和2.81,最概然机理函数为f(α)=(1-α)^(2/3)。

T-X and H-X binary phase diagrams were established according to differential scanning calorimetry(DSC)thermal analysis data of the melting process of DFTNAN/DNTF mixed system with different compositions.Composition and melting point of the eutectic of the mixed system were obtained.Viscosity,mechanical sensitivity and theoretical explosion properties of the eutectic and the mixture with melting point of 80℃were investigated.Effects of different heating rates and additives on the melting process of eutectic were studied.Finally,dynamics parameters E_(a) and A of eutectic melting process,and the most probable mechanism function were obtained by Satava-Sesták,Coats-Redfern and general integral equations.Results show that m(DFTNAN):m(DNTF)eutectic calculated from T-X and H-X phase diagrams are 62.9437.06 and 62.8837.12,respectively.And the eutectic temperature is 63.84℃.By adjusting the ratio of composition,the mixing system can not only reach the process temperature(≥80℃)required by the casting process,but also maintain a high energy level and a low sensitivity.With the increase of heating rate,both initial temperature and peak temperature of the eutectic melting process delay correspondingly.After the addition of HMX or RDX,melting point of the eutectic moved back obviously.Melting kinetic parameters E_(a) and lg A of the eutectic are 32.95 kJ/mol and 2.81,and the most probable mechanism function is f(α)=(1-α)^(2/3).