Preparation Of Carbon-based Compositeparticles And Their Catalytic Performances For Thermal Decomposition Of Ammonium Perchlorate

Ammonium perchlorate(AP) is the main component of solid propellant, so the performance of AP is closely related to the properties of the propellant, and the thermal decomposition performance is an important feature of AP. To improve the performance of the thermal decomposition of AP, mainly in lowing the decomposition temperature, increasing the decomposition heat and accelerating the decomposition rate. At present, the using of the catalyst to catalytic thermal decomposition is a key method to improve the thermal performance of AP. The carbon materials and composite particles based on carbon materials as catalysts affect the performance of the thermal decomposition of AP were studied in this paper.Experimental results show that when the CNTs serve as the catalyst of AP, the low temperature decomposition stage of AP becomes weak, and the high temperature decomposition peak temperature decreases, while the apparent decomposition heat and the thermal decomposition rate increases significantly. This paper also explores the impact of changing the parameters of CNTs parameters(including the content, length, low-speed ball-milling treatment and acidification treatment) on the thermal catalytic decomposition of AP: with the increasing of CNTs catalyst content, the thermal decomposition temperature of AP reduces, and the apparent decomposition heat shows the trend of first increases and then decreases; and the short CNTs has good catalytic effect; After the low-speed ball-milling process, CNTs exhibit better catalytic performance; the CNTs which are treated by the mixed acid show better catalytic effect for AP.Graphene also shows certain catalytic effects on AP, its main effects are to make the low temperature decomposition stage of AP becomes the primary decomposition stage, weaken the high temperature decomposition stage and increase the apparent decomposition heat. Comparative analysis of different catalytic effects between the CNTs and Graphene has been made, it maybe caused by the differences of structure and performance between the one-dimensional material CNTs and the two-dimensional material Graphene.The Co/CNTs composite particles are prepared by hydrothermal synthesis method. XRD, SEM and specific surface area analysis are adopted to characterize the Co/CNTs composite particles, when 2wt.% Co/CNTs as the catalyst of AP, the low temperature decomposition peak of AP was disappeared, and the high temperature decomposition peak appears at 305 ℃, earliering 128 ℃ than pure AP, and the apparent decomposition heat reached 1354 J/g, increased by 935 J/g compared with AP, it proves that the Co/CNTs shows good catalytic effect to AP.Zn O/Graphene composite particles are prepared by liquid phase precipitation method. XRD, SEM, TG and specific surface area analysis are adopted to characterize the Zn O/Graphene composite particles. The results show that when 2wt.% Zn O/Graphene as the catalyst of AP, the low-temperature decomposition peak appears at 270 ℃, and the high temperature decomposition peak appears at 285 ℃, compared to pure AP, the decomposition temperature decreases by 45 ℃ and 148 ℃, the apparent decomposition heat is 1270 J/g, increased by 851 J/g. the results prove that the Zn O/Graphene composite particles also shows good catalytic effect to AP.Mechanism analysis that the special structure of carbon materials and the good thermal conductivity are the key to the catalytic thermal decomposition of AP, at the same time, the unique structure of carbon materials and thermal conductive performance can further promote the metal and metal oxide catalysts for catalytic decomposition of AP.