Study On Enhancing The Thermal Decomposition Performance Of Ammonium Perchlorate Based On Alginate

In recent years,improving the combustion performance of solid propellant has been the focus and hotspot.Ammonium perchlorate?AP?,as the most commonly used oxidant,is the main component of composite solid propellant.In order to obtain higher burning rate of composite solid propellant,it is very important to improve the thermal decomposition of AP.Adding catalysts is an important method to effectively improve the thermal decomposition performance of AP,especially the transition nano metals,oxides and related composite as catalysts.However,due to its small size,large surface area,easy agglomeration and uneven distribution,nano-catalysts reduce the surface active sites,which have a great impact on the thermal decomposition performance of AP.Natural biomaterials are widely considered as an ideal candidate material in various fields due to their advantages of non-toxic,good biodegradability,low cost,easy-availability and environmentally friendly.Based on natural biomaterials-sodium alginate?SA?has received extensive attention in the field of catalysis.In order to solve the agglomeration problem of nano-catalysts in the application of AP and improve the thermal decomposition performance of AP,inspired by natural biological alginate,we prepared novel alginate/ammonium perchlorate composite by in situ synthesis,and the structure,morphology and properties of the composite were characterized by various means.The catalytic effect of these alginates on the thermal decomposition of AP was studied,and the mechanism for thermal decomposition of AP was preliminarily discussed.The main research contents include the following aspects:?1?Using the syringe injection,in situ synthesis of cobalt alginate/ammonium perchlorate?CA/AP?composite was prepared by ionic cross-linking solidification.We investigated the thermal decomposition of in situ synthesis of CA/AP composite with different cobalt nitrate solutions by DSC.Meanwhile,the possible mechanism of catalytic thermal decomposition of AP was discussed.Compared with pure AP,the DSC results indicated that the thermal decomposition temperature of in-situ synthesis CA/AP composite was decreased by 92.7°C.It significantly improved the catalytic effect on the thermal decomposition of AP.?2?Using the air ato-mization,in situ synthesis of copper alginate/ammonium perchlorate?Cu-alginate/AP?composite was prepared by ionic cross-linking solidification.The SEM results showed that the Cu-alginate had a porous structure and irregular flower-like shape,and showed a rather smooth and clean surface.The impact and friction sensitivity tests indicated that the impact sensitivity of Cu-alginate/AP composite H₅₀ was 44.8 cm,and the explosion probability of friction sensitivity was 0%.Compared with pure AP,the impact sensitivity and friction sensitivity of the composite were significantly decreased.In addition,we investigated the thermal decomposition of in situ synthesis of Cu-alginate/AP composite with different copper nitrate solutions by DSC.Meanwhile,the possible mechanism of catalytic thermal decomposition of AP was discussed.Compared with pure AP,the DSC results indicated that the thermal decomposition temperature of Cu-alginate/AP composite was decreased by 90.3°C.It significantly improved the catalytic effect on the thermal decomposition of AP.?3?Using the air ato-mization,in situ synthesis of the bimetallic CoMn-alginate/AP composite was prepared by ionic cross-linking solidification.We investigated the thermal decomposition of in situ synthesis of bimetallic CoMn-alginate/AP composite with different mass ratios of AP and SA and different molar ratios of Co?NO₃?₂ and Mn?NO₃?₂ by DSC.Meanwhile,the possible mechanism of catalytic thermal decomposition of AP was discussed.The DSC results indicated that bimetallic CoMn-alginate/AP composite was decreased by122.9°C.Compared with single metal Co-alginate and Mn-alginate,bimetallic CoMn-alginate obviously had better catalytic activity for thermal decomposition of AP.All results indicated that the bimetallic CoMn–alginate had a greater synergistic effect on the thermal decomposition of AP.