FOX-7合成过程中硝化反应的热危险性

Thermal Hazards of Nitration Reaction in the Synthesis of FOX-7

利用全自动反应量热器(RC1e)测定了1,1-二氨基-2,2-二硝基乙烯(FOX-7)合成过程中的硝化反应热释放速率及传热系数、比热容。结果表明硝化反应加料过程中的平均放热速率约为80 W,保温反应过程中的平均放热速率约为40 W,物料放热量为375.22 kJ·mol-1,理论绝热温升为483.8 K。采用差示扫描量热法(DSC)和热重-微商热重(TG-DTG)法分析了中间体2-(二硝基亚甲基)-5,5-二硝基嘧啶-4,6-二酮的热稳定性,其分解分为两个阶段,起始分解温度为30℃,第一阶段分解峰温为67.01℃,放热量为201.2 J·g-1;第二阶段分解峰温为87.15℃,放热量为1046.6 J·g-1,表明中间体的热稳定性较差。

The thermodynamic data of heat flow curve,heat transfer coefficient and heat capacity in nitration reaction of 2-meth-ylpyrimidine-4,6-dione in the synthesis of 1,1-diamino-2,2-dinitro ethylene（FOX-7）were measured by using reaction calorimeter （ RCle）. Results show that the average heat release rate of nitration reaction in feeding is about 80W and in the finishing period about 40W. The total exothermic heat of nitration reaction is 375. 22 kJ·mol-1 ,and the adiabatic temperature rise is 483. 8 K. The thermal behaviors of 2-dinitromethylene-5,5-dinitropyrimidine-4,6-dione were analyzed by differential scanning calorimeter and thermo-gravimetry-derivative thermogravimetric analysis techniques. Results show that its thermal decomposition process can be divided into two stages. The initial decomposition temperature is 30 ℃,the peak temperature of first-stage is 67. 01 ℃ and the enthalpy of decomposition reaction is 201. 2 J·g-1. The peak temperature of second-stage is 87. 15 ℃ and the enthalpy of decomposition reaction is 1046.6 J·g-1. This indicates that the thermal stability of 2-dinitromethylene-5,5-dinitropyrimidine-4,6-dione is bad.