二苯胺对硝化棉的等温热分解动力学的影响

Effects of Diphenylamine on Isothermal Thermal Decomposition Kinetics of Nitrocellulose

为研究二苯胺(DPA)对硝化棉(NC)的等温热分解动力学的影响,采用等温热分解量气装置,获得378.15~398.15 K时NC/DPA(3%)混合样品热分解产生气体的压力随时间变化曲线,该曲线中存在明显的拐点。通过Arrhenius方程和模式配合法获得NC/DPA(3%)混合样品在拐点前和拐点后的等温热分解动力学参数。采用Berthelot方程外推得到不同温度下NC/DPA的贮存寿命。结果表明,拐点前NC/DPA(3%)混合样品的活化能为164.6 kJ·mol^-1,拐点后NC/DPA(3%)混合样品的活化能为150.4 kJ·mol^-1;与原料NC相比,拐点前NC/DPA(3%)混合样品的活化能提高17.7 kJ·mol^-1;以分解深度0.1%作为评判标准,室温下NC/DPA(3%)混合样品可贮存18.3年,表明添加3%DPA后可延长NC贮存寿命7.7年。

The influence of diphenylamine(DPA)on the thermal stability of nitrocellulose(NC)was investigated by isothermal decomposition kinetics.Pressure versus time curves of the gas generated by the thermal decomposition of NC/DPA(3%)mixed sample at 378.15-398.15 K were obtained by using the isothermal decomposition gas metering device.There is a visible inflec-tion point in this curve.The thermal decomposition kinetic parameters of NC/DPA(3%)composite were calculated by Arrhenius equation and model-fitting method.The storage life of NC and NC/DPA composite was estimated using Berthelot equation.The results show that the activation energy of NC/DPA(3%)before the inflection point is 164.6 kJ·mol^-1,and the activation energy of NC/DPA(3%)mixed sample after the inflection point is 150.4 kJ·mol^-1.Compared with the NC raw material,the activation energy of NC/DPA(3%)before the inflection point is increased by 17.7 kJ·mol^-1.With a decomposition extent of 0.1%as the criterion,the storage life of NC/DPA(3%)at room temperature is 18.3 years,indicating that the storage life of NC can be ex-tended by 7.7 years after the addition of 3%DPA.