二苯胺对硝化棉的等温热分解动力学的影响

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。

Effects of Diphenylamine on Isothermal Thermal Decomposition Kinetics of Nitrocellulose

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 inflection 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 extended by 7.7 years after the addition of 3%DPA.