Reaction Mechanism of Forming Pore in HTPB/ADN Propellants
XU Hui-xiang,PANG Wei-qiang,LI Yong-hong,ZHANG Nan-nan,WANG Xiao-hong(Xi'an Modern Chemistry Research Institute,Xi'an 710065,China)
In order to reveal the reasons of forming pore in hydroxyl terminated polybutadiene/ammonium dinitramide/ammonium perchlorate/aluminium(HTPB/ADN/AP/Al) composite propellants,a series of propellant samples containing ADN and triethanolamine(TEA),triethanolamine trifluoroboron complex(T-313),tris(2-methylaziridinyl)phosphine oxide(MAPO),isophthaloyl-bis-(2-methylaziridine)(HX-752) were prepared,and the components of reacting with ADN and forming pore were confirmed,and the reaction mechanism was analyzed by DSC/TG-IR/MS. Results show that there are no pores in the propellant samples containing curing agents such as toluene diisocyanate(TDI),isophrone diisocyanate(IPDI) and ethanolamine bonding agents such as TEA,T-313 respectively,but the pores are formed in the samples containing aziridine bonding agents MAPO and HX-752. It is proved by DSC that there is a strong interaction between ADN and MAPO,which decreases the temperature of the main decomposition peak of ADN by about 99.7 ℃. When the mixture of ADN and MAPO (mass ratio 1:1) was heated continuously at 50 ℃ for 2 h,the gasous products N2O and NO2 are formed and detected by mass spectrum. It is considered that the aziridine bonding agents can accelerate the decomposition of ADN,which form pores in the propellants.
【CateGory Index】： V512