【作者】 付廷明；

【导师】 李凤生；

【作者基本信息】 南京理工大学 ， 材料学， 2008， 博士

【摘要】 高燃速推进剂是固体推进剂的重要发展方向之一。提高推进剂燃速可使固体火箭发动机在短时间内产生较大的推力,能满足反坦克导弹、防空导弹、机载导弹、拦截导弹和高速动能弹等对推进剂燃烧性能的要求,因此研制高燃速推进剂一直是推进剂领域的重点。添加燃烧催化剂是提高推进剂燃速最常用、最简便的方法。在众多催化剂种类中,无机纳米催化剂和有机金属催化剂由于其高度的催化活性得到了广泛深入的研究,然而无机纳米催化剂的分散与有机金属催化剂的迁移一直是这两类催化剂发展的主要障碍。使无机纳米催化剂以初级粒子的形式均匀的分散在推进剂的组分中,以及阻止有机金属催化剂在推进剂中的迁移是推进剂用燃烧催化剂亟待解决的课题。本论文通过使催化剂与纳米孔材料复合的方法,旨在实现无机纳米催化剂的充分分散及有机金属催化剂的固定。本论文第三章首先以介孔材料SBA-15为载体,通过SBA-15原粉浸渍方法制备了高分散CuO/SBA-15复合材料,研究发现SBA-15原粉中的模板剂（P123）能协助CuO在SBA-15表面上的分散。催化实验结果表明CuO/SBA-15复合材料对高氯酸铵（AP）的热分解具有优良的催化作用。添加2wt%的CuO/SBA-15使AP的高温分解峰温度降低146℃,而单独使用相同剂量纳米氧化铜时相应数值为120℃,表明CuO/SBA-15对AP的热分解具有更好的催化效果。其原因是由于CuO在SBA-15的表面具有更高的分散状态,提供了更多的催化活性位点。除此以外,制备的CuO/SBA-15复合材料还能显著提高AP/HTPB复合推进剂的燃速,添加1wt%的CuO/SBA-15使AP/HTPB复合推进剂的燃速提高9.5%,压强指数降低17%,催化效果明显优于单独使用同剂量的CuO。本章第二部分内容是通过缩合反应成功地将二茂铁（Fc）接枝到了SBA-15的表面,制备出了复合催化剂Fc-SBA-15,负载Fc的量为10.1wt%（含铁量）,实验表明二茂铁催化剂在推进剂中的迁移性得到了显著的降低,且其催化活性得到了保留。添加2wt%的Fc-SBA-15使AP的高温分解峰温度降低了64℃,添加1wt%的Fc-SBA-15使AP/HTPB复合推进剂的燃速较空白推进剂提高22%,压强指数下降26%。为了克服载体材料SBA-15不能燃烧的缺点,本文第四章以多孔炭材料为载体制备纳米复合催化剂。首先通过氢气还原的方法制备了纳米铜/活性炭复合材料（Cu/AC）,结果表明当负载量为10wt%时Cu在活性炭上具有最佳的分散状态。催化实验结果表明制备的Cu/AC复合材料对AP的热分解具有优良的催化作用。添加2wt%的Cu/AC使AP的高温分解峰温度降低了124℃,放热量增加了0.7 kJ/g。添加1wt%Cu/AC催化剂使AP/HTPB复合推进剂的燃速较空白样提高了25%,压强指数降低了8%。本章第二部分内容是通过缩合反应将二茂铁接枝到了碳纳米管的表面,制备了Fc-CNT复合催化剂,负载Fc的量达到5.5%（以铁含量计）。迁移性实验表明该催化剂在推进剂中的迁移性得到了显著的降低。添加Fc-CNT复合催化剂后能使AP/HTPB推进剂燃速提高36%,压强指数降低36%。与Fc-SBA-15相比,Fc-CNT具有更好的催化效果。可能的原因是:首先碳纳米管本身高温下可以氧化分解,因此具有更高的能量有助于燃烧;另外碳纳米管是热的良导体,有利于燃烧时热量的传递,而SBA-15的导热性能差不利于热量传递。鉴于上述研究使用的载体材料本身都不具有催化活性,为了寻找具有催化活性的纳米孔材料来代替目前的非催化多孔材料,本论文第五章合成了微孔氧化锰材料并对其催化性能进行了研究。首先合成了氧化锰八面体分子筛材料OMS-1,OMS-2和OL-1,并研究了其对AP热分解的催化性能。结果发现,合成的三种氧化锰八面体分子筛材料对AP的热分解均有显著的催化效果,其中以OMS-2的催化效果最好,添加2wt%OMS-2使得AP的高温放热峰温度降低了144℃,并使AP热分解的放热量增加0.66 kJ/g。接着合成了钴、铜、镍掺杂的氧化锰八面体分子筛材料M-OMS-1和M-OMS-2（M表示Co,Cu,Ni）,并对其进行了XRD、SEM、N₂吸附等表征。EDS测试结果表明有大量的金属离子掺杂到了OMS材料的孔道中,但OMS的结构没有受到影响。对AP热分解的实验表明,M-OMS材料对AP的热分解亦有显著的催化作用,但催化效果逊于相应的OMS材料。其机理可能是由于掺杂离子的存在阻碍了AP与MnO₂接触的几率,而其本身的催化效果又逊于MnO₂的缘故。更多还原

【Abstract】 Ammonium perchlorate（AP）/hydoxyl-terminated polybutadiene（HTPB） composite solid propellants are composed of 15 wt%HTPB as a polymeric matrix,additive with 70 wt%AP solid powder as a oxidizer,10 wt%metal powder as a secondary fuel component, and 5 wt%low-molecular-weight species such as catalyst,plasticizer,and curing agent. Though catalysts are in minute quantities,they play an important role in the performance of propellant,catalysts are required to increase the burning rate of composite solid propellant,as they have low inherent burning rate.Nanometer sized metal particles and metal oxides particles are good burning rate enhancer for composite solid propellants due to their smaller size and larger surface area.Unfortunately,the high viscosity during the propellant molding process made these nanoparticles hardly dispersed in HTPB,which diminished their catalytic effect.The ferrocene（Fc） and its derivatives are other kind of good burning rate enhancers for AP/HTPB composite solid propellants,however some defects limited the use of ferrocene derivatives as burning rate catalyst,such as their migration to insulation during curing and storage,evaporation or sublimation loss during processing,and phase separation by crystallization in low temperature applications or storage.To disperse the nanosized particle and block the migration of Fc,composite powder technology was developed in this paper,nanoporous composite powder was prepared and its catalytic activity on the thermal decomposition of AP and the combustion of AP/HTPB propellant was studied.In chapter 3,CuO/SBA-15 composites were prepared by impregnation method using as-prepared SBA-15（template concluded） as support.The resulting sample was characterized by X-ray diffraction and N₂ adsorption to evaluate the textural properties of these composites.TG-DSC was used to survey the catalysis function of the sample to the decomposition of ammonium perchlorate（AP）.Results indicated that CuO was well dispersed on the surface of SBA-15,and these materials shown significant catalytic effect on the decomposition of AP.The decomposition temperature of AP containing 2wt%CuO/ SBA-15 decreased by 146℃as compared with the decomposition temperature of pure AP. Moreover,the burning rate of AP based propellant increased 9.5%and pressure exponent decreased 17%after addition of 1 wt%CuO/SBA-15 composites.A non-migration catalyst was developed by grafting ferrocene on SBA-15 in chapter 3. The grafted catalyst has been characterized by small angle X-ray diffraction（SAXRD）, infrared spectra（IR）,N₂ adsorption,and the atomic absorption spectrophotometry （AAS）.The migration behavior has been assessed by AAS and the catalysis on the thermal decomposition of AP has been studied with differential scanning calorimetry analysis （DSC）.XRD and N₂ adsorption indicated that grafting of Fc caused the decrease of BET surface area and pore diameter,but the structure of SBA-15 was not destroyed.Fe content in HTPB slides at various distances from the interface between the non-additive and additive showed that grafted Fc was a non-migration catalyst.DSC curves indicated that grafted Fc decreased the thermal decomposition temperature of AP.Burning rate test indicated that grafted Fc increased the burning rate of AP/HTPB composite propellant and decreased the pressure exponent value.Since SBA-15 is non-energetic,it is therefore highly desirable that using energetic material as carrier for nanometal and organic ferrocene.In chapter 4,nanometer sized copper/active carbon（AC） composite material was prepared by H₂ deoxidization at 500℃. Results show that the best dispersion acquired when the copper content is 10wt%.Cu/AC composite materials have significant catalytic activity on the decomposition of AP.The decomposition temperature of AP containing 2wt%Cu/AC decreased by 124℃as compared with the decomposition temperature of pure AP.Moreover,the burning rate of AP based propellant increased 25%and pressure exponent decreased 8%after addition of 1 wt%Cu/AC（10） composites.Another non-migration catalyst was developed by grafting ferrocene on carbon nanotube（CNT） in chapter 4.The grafted catalyst has been characterized by Raman spectra and Infrared spectra.The migration behavior has been assessed by AAS and the catalysis on the thermal decomposition of AP has been studied with differential scanning calorimetry analysis（DSC）.Raman spectra and Infrared spectra indicated that Fc has been grated on CNT,Fe content in HTPB slides at various distances from the interface between the non-additive and additive showed that grafted Fc was a non-migration catalyst.DSC curves indicated that grafted Fc decreased the thermal decomposition temperature of AP by 106℃.Burning rate test indicated that grafted Fc increased the burning rate of AP/HTPB composite propellant and decreased the pressure exponent value.The better catalytic activity compared with Fc-SBA-15 may be attributed to the better heat conduction with the addition of CNT.In chapter 5,three kinds of manganese oxide octahedral molecular sieves（OMS） were prepared and the catalytic activity of OMS on the thermal decomposition of ammonium perchlorate（AP） has been briefly studied.Results show that OMS plays a catalytic role on the thermal decomposition of AP,and the most effective is OMS-2.The decomposition temperature of AP has been decreased 145℃and the heat of decomposition has been increased 0.66 kJ·g^-1 with the addition of 2wt%OMS-2.Such effects are mainly attributed to the mixed valence of Mn³⁺ and Mn⁴⁺ existing in OMS-2 material and its high surface area.Doping with Cu²⁺,Ni²⁺ and Co²⁺ does not improve the catalytic activity of OMS.更多还原