Study On The Synthesis And Their Applications Of Nitro-fullerene Derivatives

This paper includes three parts:preparation of fullerene,the theoretical design and synthesis of novel pyrrolidine nitro-derivatives,the investigation of the application of fullerene and its derivatives in high energetic explosives and nitramine modified double base propellant(RDX-CMDB).The fullerence soot is preparated with graphite by arc discharge method.The yield of fullerene is 9.0%under the optimum conditions:0.05MPa Helium pressure,100A direct current intensity,6 rad/min advancing velocity of graphite rod.The optimum conditions for the column chromatography separation condition of fullerence are:activated carbon,alumina and silica gel mixed in mass ratio of 2:1:1 as stationary phases,toluene as a mobile phase.Under the optimum conditions,the C₆₀ extraction rate of 60%is given and the mechanism of preparation is also discussed.The nine nitro stable fullerene derivatives have been designed,prepared and separated in accordance with the principle of Prato Reaction using TNT,fullerene,amino acids and nitrobenzaldehyde as raw materials.The reaction conditions affecting the yields of the six products of those are investigated in full detail,and the optimum synthetic technology conditions of the products are:â‘ product 1:the molar ratio of C₆₀,2-nitrobenzaldehyde and N-methyl-glycine 1:3:6,the temperature 55℃,the reaction time 12h,the volume of toluene 40ml,with the yield of 53.5%;â‘¡product 2:the molar ratio of C₆₀,3-nitrobenzaldehyde and N-methyl-glycine 1:1:2,the temperature 100℃,the reaction time 16 h,with the yield of 94.8%;â‘¢product 3:the molar ratio of C₆₀,2,4-2-nitrobenzaldehyde and N-methyl-glycine 1:2:6,the temperature 95℃,the reaction time 40 h,with the yield of 65.8%;â‘£product 5: the molar ratio of C₆₀,2-nitrobenzaldehyde and glycine 1:4:6,the temperature 80℃,the reaction time 48 h,the volume of toluene 70ml,with the yield of 81.2%;⑤product 6:the molar ratio of C₆₀,3-nitrobenzaldehyde and glycine 1:4:6,the temperature 100℃,the volume of toluene 80 ml,the reaction time 24 h,with the yield of 82.1%;â‘¥product 7:the molar ratio of C₆₀,4-nitrobenzaldehyde and glycine 1:2:4,the temperature 90℃,volume of toluene 80 ml,the reaction time 48 h,with the yield of 79.6%.For the different stereoselectiveity of the product 8 synthesized by microwave-assisted solid-phase reaction and oil bath heating solid-phase reaction,a possible reaction mechanism is put forward and explained in theory.The structures of the products are characterized by UV-vis,FT-IR,¹³C NMR,¹H NMR and MS.It proves the molecular structure of the products are the aim compounds. The thermal stability of C₆₀ and its nitro-fullerene derivatives are studied by DTA and DSC-TG.The results show that the atmosphere has a big influence on the thermal stability of C₆₀.C₆₀ begins to decompose at 423.5℃in the air,the deomposed peak temperature is 668.5℃,but very stable in the helium atmosphere,only sublimate,the crystal shape of C₆₀ has a certain influence to its thermal stability.The synthesized nine kinds of nitro-fullerene derivatives all have good thermal stability and their decomposed peak temperatures all exceed 350℃.The thermal explosion temperature for 5 seconds delay of product 4 is 253℃.The category,number and position of nitryl group in nitro-fullerene derivatives all have influence on their thermal stability.To the analogous derivatives,the bigger the number of nitro group is,the worse thermal stability is.The sequence on the thermal stability of nitro group position is:para site＞ortho site＞meta site when the number of nitro group is equal.The insensitive action of the four products on HMX is studied preliminarily.The results show that the crystal forms of fullerene have some effect to the desensitization of HMX.C₆₀ obtained through the rapid crystallization of CS₂/petroleum has the same effect on the impact sensitivity of HMX as well as Graphite,friction sensitivity is also reduced to 70%.Insensitive action of the product 2 on HMX is equivalent to that of graphite,the product 4 has a sensitization to HMX,promoting change of HMX from combustion to detonation.At the same time,the gas standard molar enthalpy of formation,standard molar enthalpy of combustion,explosion heat,detonation pressure and detonation velocity are calculated theoretically using DFT/BLYB method.The theoretical analysis has carried on to reaction mechanism of thermal decomposition of the product 4 which indicate product 4 will release larger energy in the decomposition and has the properties of new type of energetic material.The nitro fullerene derivative 2 are introduced into solid propellant firstly in simulation test,the relevance of the temperature of propellant burning surface and the catalyst is studied by flame temperature distribution experiment,and the relations of propellant burning rate with the pressure changing are obtained.The experimental result indicate that,compared toΦ-Pb for the single-component catalyst,CB and 2-FS additives could increase the burning rate of RDX-CMDB propellant obviously,and 2-FS is significantly superior to the effect of CB;compared toΦ-Pb/β-Cu for the bicomponent catalyst,CB,product 2,CF and 2-FS additives could increase the burning rate of RDX-CMDB propellant obviously,and product 2,CF and 2-FS are significantly superior to the effect of CB;for tripropellant catalyst system,the catalytic effect of FS,product 2,CF and CB increase in succession. nitro-fullerenes and p-phthalic acid lead(Φ-Pb) had better coordination catalysis,which can intensify the decomposition of condensed phase of double-base system,catalyze the reaction between the decomposition products,increase the surface temperature of catalysis,increase the propellant burning rate,reduce the pressure exponent,widen the scope of the burning platform and make it move in the direction of high pressure.