【作者】 何志伟；

【导师】 刘祖亮；

【作者基本信息】 南京理工大学 ， 应用化学， 2010， 博士

【摘要】 多氨基多硝基吡啶氮氧化物的代表化合物2,6-二氨基-3,5-二硝基吡啶氮氧化物(ANPyO)和2,4,6-三氨基-3,5-二硝基吡啶氮氧化物(INPyO)是一类新型的含能材料,具有感度低,成本低,稳定性好,耐热性好以及较高的爆炸性能,是潜在的高能钝感炸药候选物,在含能材料领域具有广阔的应用前景。本论文分别以三氟乙酸(CF3COOH)、二甲基亚砜(DMSO)和N,N-二甲基甲酰胺(DMF)为溶剂,采用重结晶法精制ANPyO或TNPyO,对精制后样品性能进行比较分析。结果表明：分别用CF3COOH重结晶的ANPyO和TNPyO平均粒径最小,比表面积分别为0.454m2·g-1和2.760m2·g-1;10℃·min-1温升速率时,热分解峰值温度分别为370.69°C和355.9℃,表观活化能分别为279.63kJ·mol-1和303.15kJ·mol-1；机械感度最低。CF3COOH是最佳的重结晶溶剂。结晶工艺条件对ANPyO的晶型和感度也有明显的影响。采用溶液-水悬浮-蒸馏法,分别以氟橡胶F2311和丁腈橡胶(NBR)包覆ANPyO和TNPyO,利用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、差示扫描量热法(DSC)、热重分析法(TG)和感度试验表征包覆前后ANPyO和TNPyO的结构和性能。试验结果表明：分别用F2311和NBR包覆后的ANPyO和TNPyO热分解峰值温度降低,分解热提高,分解深度减小；包覆后颗粒变大,红外光谱中N-H特征峰和氮杂原子的特征峰均发生偏移；机械感度均降低。包覆能改善ANPyO和TNPyO的能量和机械感度性能,其中以F2311包覆的ANPyO和TNPyO性能更优。根据ANPyO和TNPyO及其配方分别在不同升温速率下TG的分析结果,分析讨论了它们的热分解过程,用非线性等转化率积分法和Ozawa法计算了它们的热分解活化能、指前因子等动力学参数和机理函数。ANPyO和TNPyO及其配方的热分解机理均属于n=1的随机成核和随后生长。采用绝热加速量热仪对ANPyO和TNPyO及其配方进行绝热分析。利用速率常数法计算了它们绝热分解的活化能和指前因子等动力学参数。依据绝热分解过程的温度、压力、温升速率随时间的变化以及计算结果对它们的热安全性进行评价。采用热重-微商热重分析(TG-DTG)、热重与质谱联用(TG-MS)和原位热裂解快速扫描傅里叶变换红外等技术研究了ANPyO的热分解全过程,并通过跟踪测试热分解过程中气相和凝聚相产物及其变化情况提出了ANPyO的热分解机理。研究结果表明：ANPyO的热分解过程是分步进行的,首先是吡啶环上相邻的-NH2和-NO2发生环化反应放出NO；然后是吡啶环开环分解,放出CO、HCN、CO2等气体。制备以ANPyO、橡胶类粘结剂和增塑剂组成的耐热混合炸药,进行了耐热性、成形性、爆炸和感度性能测试。结果表明：以ANPyO为基耐热炸药有良好的耐热性能,可以在200～250℃温度条件下使用；成形+性能良好；机械感度均低于单质ANPyO。将ANPyO应用于石油射孔弹中,对其压药成形性、破甲性能和作功能力进行了测试分析,含NBR配方的成形性和破甲性能均最好。利用密度泛函理论对ANPyO晶体进行计算。导带较平伏,价带起伏较大且为非简并态。导带轨道主要由碳原子、氧原子和氨基N原子的原子轨道组成,而价带轨道由碳原子、氨基和硝基原子的原子轨道组成。当晶体沿a和c方向被压缩时,两者的电荷分布变化几乎相同；但沿b方向压缩时,产生不同的电荷分布,表明晶体被压缩时的各向异性。C-N(硝基)和N-O(氮氧化物)最弱,受外界影响最易断裂。经校正基组叠加误差后,ANPyO的晶格能为-166.03 kJ·mol-1。晶体中N-O (N-oxide)键的Mulliken布居数远小于分子中该键的Mulliken布居数,表明由于分子的堆积作用导致晶体中该键变弱。这与ANPyO撞击感度高于TATB的实测结果相一致。从分子水平揭示了ANPyO的低感度(但感度高于TATB)等性质。为了解ANPyO对硝胺炸药的降感效果,利用结晶包覆法制备了ANPyO/RDX和ANPyO/HMX的复合物,并与混合法制备的样品进行比较。利用SEM、DSC、感度和爆速测试等方法比较复合物样品的结构和性能。结果表明：结晶包覆法制备样品中ANPyO对硝胺炸药的包覆效果比混合法的包覆效果要好；样品的平均粒径均处于硝胺炸药与ANPyO之间；样品的分解峰值温度均低于硝胺炸药；样品的机械感度均比硝胺炸药低,结晶包覆法制备样品机械感度下降更显著。制备了以硝胺炸药为基,ANPyO为钝感剂,不同橡胶为粘结剂的高聚物粘结炸药造型粉样品,并且对其进行结构和性能测试,表明高聚物粘结炸药样品的机械感度明显低于硝胺炸药,爆速比ANPyO显著提高。更多还原

【Abstract】 2,6-Diamino-3,5-dinitropyridine-l-oxide(ANPyO) and 2,4,6-triamino-3,5-dinitropyridine (TNPyO) are the representative compounds of polyamino and polynitro derivatives of pyridine and their N-oxides are novel energetic materials. ANPyO and TNPyO may be potential insensitive high energy explosive candidates with low mechanical sensitivity and cost, good stability and heat resistance, and high energy. They have a wide applied future in the energetic material field.The fine samples of ANPyO or TNPyO were respectively prepared by recrystallization from the solvents of trifluoroacetic acid(CF3COOH), dimethyl sulfoxide(DMSO) and N,N-dimethyl formamide(DMF) in the paper. The properties of the samples of ANPyO and TNPyO were compared. Results show that the average particle sizes of ANPyO and TNPyO that were prepared by recrystallization from CF3COOH are the smallest, their BET specific surface area are respectively 0.454m2·g-1 and 2.760m2·g-1; The thermal analysis and thermal decomposition kinetics calculation indicate that the temperatures of the exothermic peaks of ANPyO(CF3COOH) and TNPyO(CF3COOH) are the highest, the results are respectively 370.69℃and 355.9℃at 10℃·min-1 heating rate, and their activation energy are respectively 279.63kJ-mol-1 and 303.15kJ·mol-1; Mechanical sensitivity of ANPyO and TNPyO that were prepared by recrystallization from CF3COOH are respectively the lowest.ANPyO and TNPyO were coated with fluorine rubber F2311 and nitrile-butadiene rubber(NBR) by means of solution-water suspending-distillation method. The structures and properties of ANPyO, TNPyO and coated samples were characterized by fourier transform infrared spectroscopy(FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermograimetry (TG), and mechanical sensitivity test. The results show that the decomposition peak temperatures of coated ANPyO and TNPyO are lower, decomposition heats are higher, decomposition depths are smaller than uncoated ANPyO and TNPyO; It is found that particles of ANPyO and ANPyO become bigger; In FTIR spectra, N-H and nitrogen atom in pyridine spectral characteristic absorption bands have shifted; Mechanical sensitivity of coated ANPyO and TNPyO become lower respectively. Energy and mechanical sensitivity performance of ANPyO and TNPyO can be improved by coating, the performance of ANPyO and TNPyO coated by F2311 are better than NBR.The thermal decomposition processes of ANPyO, TNPyO and their formulations were studied by TG curves at different heating rates. The thermal decomposition kinetic parameters, such as activation energy, pre-exponential factor and reaction order, and the mechanism functions of ANPyO, TNPyO and their formulations were obtained by the integral iso-conversional non-linear method and Ozawa’s method. The results show that the thermal decomposition mechanism of ANPyO and TNPyO and their formulations are classified as random nucleation and growth of n=1. Adiabatic thermal decomposition of ANPyO, TNPyO and their formulations have been investigated using accelerating rate calorimetry. Kinetic parameters, such as activation energy, pre-exponential factor and reaction order are calculated using reaction rate method. Thermal safety of ANPyO, TNPyO and their formulations have been evaluated according to temperature, pressure and temperature rise rate in thermal decomposition and calculation results.Thermal decomposition processes of ANPyO were investigated by using, TG-DTG, TG-MS, coupling techniques and in-situ thermolysis rapid scan-FTIR coupling technique. Mechanism of ANPyO thermal decomposition was presented by tracking test gaseous and agglomerate productions and their change in the thermal decomposition. The results show that the thermal decomposition process of ANPyO can be divided into steps, the ring reaction occur between-NH2 and adjacent-NO2 of pyridine ring, and releasing NO in the first step, and then pyridine ring decompose and release CO, HCN and CO2 etc gases.Some heat resistant composite explosives composed of ANPyO, some polymer binders containing fluorin and little heat resistant plasticizer were prepared. The performance tests were conducted by measuring the heat resistance, formability, explosion energy and sensitivity. The results show that the ANPyO-based heat resistant composite explosives have good heat resistance and formability, indicating that heat resistant composite explosives can be used in the temperature range of 200～250℃; Their mechanical sensitivity is vicinal and lower than that of ANPyO individual explosive. Performance of formability, penetration and power capability of ANPyO applied in the petroleum perforator were tested, performance formability and penetration of formulations containing NBR are the best among the all formulations.Density functional theory calculations were performed on crystalline ANPyO. The conduct bands are generally quite flat, while the valence bands are degenerate. The carbon, oxygen and amino nitrogen atoms make up the narrow lower energy bands. While the carbon, amino nitrogen and atoms in nitro group make up the higher energy bands. Change of electronic charges for the decrease of the cell edge a and c are almost the same, but different from the decrease of the cell edge b, indicating an anisotropic effect related to compressions. The C-Nitro and the N-0 (N-oxide) bonds are the weakest, and tend to rupture upon external stimulation. The crystal lattice energy is predicted to be-166.03kJ/mol, after being corrected for basis set superposition error. The Mulliken population for the N-0 (N-oxide) bond in crystal is much smaller than that in molecule, indicating that the molecular packing weakens this bond. Judged by the fact of N-0 (N-oxide) bond being weaker than C-Nitro bond, ANPyO is sensitive to mechanic impact than 1,3,5-triamino-2,4,6-trinitrobenzene, which is in good agreement with experiment. The performances of ANPyO such as low sensitivity were illuminated from molecular level.In order to know the desensitizing efficiency of ANPyO on nitroamine explosives, ANPyO/RDX and ANPyO/HMX composites were prepared by crystal coating and mixing method respectively. The structures and properties of the samples were characterized by SEM, DSC, mechanical sensitivity and detonation velocity tests. Results show that ANPyO has a better coating on nitromine explosives in crystal coating than mixing method; The average particle sizes of the samples are situated between ANPyO and nitromine explosives; The decomposition peak temperatures of the samples are lower than that of nitromine explosives; Mechanical sensitivity of the samples are lower than that of nitromine explosives, and mechanical sensitivity of the samples in crystal coating decreased more significant. The nitromine explosives-based polymer bonder explosive(PBX) samples were manufactured with ANPyO deterrent and different rubber binder. The structures and properties of the samples were tested. Results show that mechanical sensitivity of PBX samples are lower than that of nitromine explosives, detonation velocity of PBX samples are distinct higher than ANPyO.更多还原