Synthesis And Catalytic Performance Of Dinuclear Ferrocene Triazole Ionic Metal Complexes

The combustion performance of a solid propellant is the main factor affecting the ballistic performance of the missile and is usually adjusted by adding a burning rate catalyst(BRC)in the solid propellant.Ferrocene compounds,due to their excellent regulatory functions,have become a type of widely used BRC in composite propellants.At present,the commercialized ferrocene-based BRCs have the problems of strong migration tendency,high volatilization and easy aging by oxidation during the processing and storage of the propellants,which leads to the decrease of the storage life of the propellant drug column and the increase of the military expenses.Therefore,it is very important to develop new types of ferrocene-based BRCs with high thermal stability,strong anti-oxidation ability,low migration,and high catalytic activity.In this thesis the concept of nitrogen-rich and synergetic catalysis was introduced into the studies on ionic ferrocenyl burning rate catalyst.A series of novel dinuclear ferrocenyltriazole derived ionic metal complexes were designed and synthesized and their molecular structures were characterized and performances were evaluated.The main research contents of this thesis is as follows:(1)4-amino-3,5-bis-(4-ferrocenyl-1,2,3-triazolyl-1-methyl)-1,2,4-triazole(BFcTAz)with high nitrogen content(22.15%nitrogen content),high iron content(40.87%ferrocene content)and better coordination ability was synthesized by means of click reaction,then employing BFcTAz as the ligand,Cr(NO3)3·9H2O,MnSO4·H2O,Fe(NO3)3·9H2O,CoSO4·7H2O,Ni(NO3)2·6H2O,Cu(NO3)2·3H2O,Zn(NO3)2·6H2O,Cd(NO3)2·4H2O and Pb(NO3)2 as the cationic sources,energetic compounds sodium picrate,sodium stearate,sodium trinitroresorcinate,potassium 1,1,3,3-tetracyanopropene,pyridinium 1,1,2,3,3-pentocyanine and tetraethylammonium 1,1,2,5,6,6-hexacyano-3,4-diazahexadiene as anionic sources,54 ionic metal complexes derived from BFcTAz were synthesized.The ligand was characterized by 1H NMR,13C NMR and single crystal X-ray diffraction.The structures of the complexes were characterized by FT-IR,UV/Vis,EA,and TG.(2)The redox properties of the complexes were tested by cyclic voltammetry.The results showed that the oxidation potentials of the new complexes were higher than those of n-butylferrocene,tert-butylferrocene and catocene,indicating that their antioxidant capacities are higher than those of neutral ferrocenes.Additionally,the studies on the dependence of peak potentials of some complexes on scanning speed demonstrated that there is a linear correlation between the peak current of a complex and the square root of the scanning rate,which shows that the electrochemical reaction process of the complexes is controlled by diffusion process.(3)The thermal stability of the complexes was evaluated using TG technology.The results showed that the loss of the crystalline water in a complex occurred before 120?,followed by the loss of the coordination water before 220?,and the complex skeleton collapsed after 200 ?.Compared with the commercialized burning rate catalyst catocene in thermal stability,the synthesized complexes have better thermal stability.(4)Their catalytic activities of the synthesized complexes in the thermal degradation of ammonium perchlorate(AP),1,3,5-trinitro-1,3,5-triazacyclo-hexane(RDX),1,2,5,7-tetranitro-1,3,5,7-tetraazacyclooctane(HMX)and 1,1-diamino-2,2-dinitroethylene(FOX-7)were examined by DSC technique.The results indicated that all the new complexes with the optimum weight percentage(4 wt.%or 5 wt.%)in AP can narrow the wide decomposition temperature range of AP,and the peak temperature of AP is turned from an endothermic process to an exothermic process peaked in the region of 313.6-370.1?(59.2-115.7? downwards-shift).Meanwhile,the heat release of AP increased during the whole stage.Of the new compounds,the 43 exhibits the most significant effect on the thermal decomposition of AP with a released heat of 1749.6 J·g-1 For the compounds with same anions,the complexes 7,8,16,17,26,34,43,44 and 52 with Cu or Zn as central metal ions have stronger catalytic effect and can increase the heat release of AP to 1404.4-1749.6 J·g-1.The new complexes can advance the exothermic decomposition peak temperature of RDX slightly,and most of them can increase the heat release of RDX.The new compounds containing same anions,7,16,34,43 and 52,exhibit significant effect on the thermal decomposition of RDX,with the released heats being higher by 253.5-395.2 J·g-1 than that of the standard RDX,and the compound 43 exhibiting the strongest effect(1330.3 J·g-1).Moreover,the new compounds exhibit significant effect on the thermal decomposition of FOX-7,with the exothermic decomposition peak temperature of FOX-7 being advanced by 0.3-17.9 ?.In addition,most of the new compounds exert highly catalytic efficiency in the thermal degradation of FOX-7 than that of catocene.Among them,the complexes with Cu as the central metal ions have more excellent catalytic ability,of which compounds 7,16,25,34,43 and 52 can increase the heat release of FOX-7 by 27.6-265.1 J·g-1.The catalytic effect of the new complexes on the thermal decomposition of HMX is,however,not obvious.(5)The thermal behavior of RDX catalyzed by compounds 31,37 and 43 and HMX catalyzed by compounds 33 and 42 were studied under non-isothermal conditions by DSC method.The Kissinger equation,Ozawa equation and integral method were employed to determine kinetic parameters and thermal decomposition mechanism functions.The data show that the compounds have an obvious catalysis on the decomposition peak temperature of RDX and HMX and the lowering of their activation energies.Compared with the activation energy of the standard RDX,the compounds 31,37 and 43 can reduce RDX activation energy by 3.53 kJ·mol-1,16.94 kJ·mol-1 and 21.82 kJ·mol-1,based on the calculation of the Kissinger equation and the Ozawa equation.Similarly,compared with the activation energy of the standard HMX,the compounds 33 and 42 decrease HMX activation energy by 50.16 kJ·mol-1 and 78.78 kJ·mol-1,respectively,which is positively correlated with the catalytic activity of the above compounds on the thermal decomposition of both RDX and HMX.In summary,the synthesized complexes have excellent catalytic effects on the thermal degradation of AP,RDX and FOX-7,especially the copper metal complexes;exhibit more excellent catalytic ability and have potential application values.