表面活性剂改善硝酸铵吸湿性研究

用表面活性剂对硝酸铵进行表面改性处理 ,测定了改性硝酸铵的吸湿性。结果表明 ,表面活性剂能有效地降低硝酸铵的吸湿率 ,改性硝酸铵的吸湿率比普通硝酸铵降低约 30 % ,并得出了较为理想的硝酸铵改性表面活性剂。     

聚苯乙烯包覆硝酸铵改善吸湿性的研究

采用相分离法制备了聚苯乙烯(PS)包覆硝酸铵(AN),研究了甲苯和正己烷体积比、聚苯乙烯与硝酸铵质量比、混合溶剂与硝酸铵配比、沉淀剂加入速度等因素对聚苯乙烯包覆硝酸铵性能的影响。用吸湿降低率评价聚苯乙烯对硝酸铵包覆程度。结果表明,聚苯乙烯包覆硝酸铵的较佳工艺条件为甲苯与正己烷体积比为1∶3,混合溶剂/AN=3.5 mL/g,室温,沉淀剂滴速10滴/min。包覆60目硝酸铵,PS质量分数为1.54%,包覆AN吸湿降低率75%。硝酸铵目数增大,达到相同吸湿降低率,PS用量显著增大。     

阳离子型偶联表面活性剂改性硝酸铵性能研究

对阳离子型偶联表面活性剂膨化处理的改性硝酸铵进行了电镜扫描、孔径与孔容分布、粒径分布、比表面积、抗吸湿结块性及爆炸性能的实验研究，结果表明：同普通硝酸铵相比，阳离子型偶联改性硝酸铵的晶形不规则，富含气孔；比表面积大，可达3869．56cm^2／g；95％有效孔径处于介孔范围，有较小的粒径范围，主要分布在10～1000μm范围内；并且有良好的抗吸湿结块性，改性硝酸铵的吸湿率比普通硝酸铵的吸湿率降低约60％，抗压破坏力仅为普通硝酸铵的1／6，用其制得的粉状工业炸药具有更好的物理性能和爆炸性能。     

微胶囊技术在硝酸铵改性中的应用

提出了用聚苯乙烯包覆硝酸铵制备硝酸铵微胶囊的新方法 ,采用电子能谱仪研究了包覆效果 ,并对包覆前后的硝酸铵进行吸湿性测量 ,分析了改性后的硝酸铵吸湿结块性降低的原因和机理。     

新型表面活性剂改性硝酸铵的研究

选用阳离子表面活性剂、阴离子表面活性剂以及两种表面活性剂复合后的改性剂对硝酸铵进行表面处理,测定了改性前后硝酸铵的表面接触角、表面张力以及在特定温湿度条件下的吸湿率。结果表明,改性后硝酸铵的吸湿性得到了较好地改善,并得出复合型表面活性剂的改性效果最好,吸湿率下降了87.2%。     

硝酸铵吸湿点测定方法的改进及影响因素

吸湿点是硝酸铵在用作固体推进剂时的重要指标之一。通过实验对吸湿处理的方法进行了改进,并从温度、称样量及样品表面积3个方面对硝酸铵吸湿点测定的影响进行了分析。依据实验得出的数据,将吸湿处理的方法改进为在25℃的恒温环境中、90%的相对湿度下吸湿3 h。在影响因素中,温度对其影响最明显;称样量对吸湿点的测定影响比较小,但使称样量尽量接近会减小平行差;表面积对吸湿点测定的影响较大。     

甲基紫法对单基硝酸铵发射药安定性的研究

采用甲基紫法研究单基硝酸铵发射药的安定性,探讨了硝酸铵含量、吸湿性及包覆层厚度对单基硝酸铵发射药安定性的影响。结果表明:在发射药中添加一定含量的硝酸铵制成单基硝酸铵发射药后,其安定性符合要求;随硝酸铵含量增加发射药安定性增加;硝酸铵发射药吸湿后安定性降低;包覆层数对其安定性影响不大。     

虫胶包覆硝酸铵工艺研究

利用物理化学包覆的相分离原理,以虫胶为包覆剂、正丁醇为溶剂、正己烷为沉淀剂包覆硝酸铵,降低其吸湿性,用硝酸铵的吸湿率表征包覆效果。对正丁醇与正己烷配比、混合溶剂用量、沉淀剂滴加速度、虫胶用量等影响吸湿性的因素进行了研究。结果表明,正丁醇与正己烷体积比为1:3,混合溶剂与硝酸按配比为5.0 mL/g,沉淀剂滴加速度为6s/滴,虫胶用量与粒径成反比。在较佳包覆条件下,虫胶包覆硝酸铵可使吸湿率下降55%。     

Gemini表面活性剂C12-3(OH)-C12·2Cl对膨化硝酸铵晶体性能影响的研究

本文通过对Gem in i表面活性剂C12-3(OH)-C12.2C l及其单体表面活性剂DTAB分别处理的膨化硝酸铵进行晶体接触角、表面能、比表面积、晶变特性、抗吸湿结块性及爆炸性能的实验研究,结果表明,同DTAB处理的膨化硝酸铵相比,C12-3(OH)-C12.2C l改性的膨化硝酸铵的晶体接触角较大、表面能较小、比表面积大,晶变热降低且晶变点后移,有良好的抗吸湿结块性,用其制得的粉状工业炸药具有更好的物理性能和爆炸性能。     

螯合型硝酸胺改性剂的合成及其应用研究

以钛酸酯偶联剂为起始原料,与丙二酸反应得到螯合型丙二酸钛酸酯,再发生酯交换反应,制备得到螯合型表面改性剂。通过FT-IR对相关化合物进行了结构表征,结果表明所得结构与预期产物的结构相一致。用螯合型钛酸酯改性剂对硝酸铵采用液相分离法改性,改性后硝酸铵颗粒表面有包覆层。与未改性的硝酸铵相比,改性硝酸铵的吸湿率下降了69.74%。     

硝酸铵氧化剂的表面改性及其吸湿性研究

提出了用硅烷偶联剂Si-K和高分子材料Polym-B对硝酸铵进行双层包覆的新思路;利用光电子能谱仪和扫描电子显微镜表征了包覆效果,结果表明Si-K和Polym-B能对硝酸铵粒子进行很好包覆,在其表面形成均匀而完整的包覆层.通过测量吸湿性和结块性的变化研究了改性效果,数据表明改性后的硝酸铵吸湿性降低了近50%,结块性显著降低.     

包覆硝酸铵发射药吸湿性和安定性研究

为研究包覆硝酸铵(AN)发射药的吸湿问题,用硝化棉(NC)对不同AN含量的AN发射药进行了不同层数的包覆,然后对未包覆和包覆试样进行了平衡干燥器法吸湿测试和真空安定性试验。结果表明:在温度为30℃、相对湿度为90%的条件下,AN发射药的吸湿量随着AN含量的增加而增加;包覆层有效抑制了吸湿性,提高了AN发射药的安定性。     

微胶囊对无机盐的改性研究

利用物理化学原理进行相分离，利用壁材凝聚包覆的物理化学方法，对硝酸铵进行包覆，使硝酸铵的吸湿性和结块性得到改善；对产物进行分析，得到产物与硝酸铵的性质对比数据；并讨论了影响产物质量的因素。实验结果表明：利用微胶囊技术对硝酸铵进行改性，在一定条件下是可行的，并达到了缓释的目的。     

Effect of polymer coating on ammonium nitrate substrate

Prilled, spheroidized, and granular ammonium nitrates (AN) were coated with poly(chloro-p-xylylene) (parylene C) by a vapor deposition polymerization technique. Particles of AN with a 0.2% coating remain free flowing after long exposure to ambient conditions. The effectiveness of the coating as a moisture barrier on the three forms of AN was found to be in the order spheroids > prills > granules. Water adsorption isotherms and hygroscopicity determinations indicate that a 0.7% coating hydrophobes the surface of AN by approximately one order of magnitude. The parylene C/AN interface exhibits chemical and physical stability at elevated temperatures.     

乙二胺反应型包覆硝酸铵及其在叠氮聚醚推进剂中的应用

为改善含相稳定硝酸铵(PSAN)推进剂的力学性能,用乙二胺与PSAN颗粒表面反应,制备了乙二胺反应型包覆PSAN。FTIR证实乙二胺与AN之间发生了化学反应。通过吸湿性、接触角测量,对包覆效果进行了表征。结果表明,包覆后PSAN的表面极性明显降低,吸湿性也有一定程度改善。将包覆后的PSAN应用到BAMO-THF推进剂中,发现乙二胺包覆量为0.2%时对推进剂力学性能的改善效果最好,σm提高约46%,εm提高约83%。     

改性铵油炸药研究

通过对普通硝酸铵进行改性制得一种多微孔改性硝酸铵,并对其物理性能和爆炸性能进行了深入研究。研究结果表明,改性铵油炸药具有较低的吸湿性和结块性,吸油性好,不渗油,是一种爆轰感度高、爆炸性能优良的新型工业炸药。     

Characteristic Properties of AN/GAP-Propellants

Formulations based on ammonium nitrate and GAP are promising candidates for the development of high energetic, minimum smoke propellants with reduced sensitivity to be applied for radar and laser guided tactical missiles. The difficulties for the development of such a propellant system depend on the chemical nature and problems connected to the ingredients. Drawbacks are caused by the numerous phase changes of AN, its hygroscopicity, lower energy and low reactivity. The key problems for the development are the unfavourable combustion behaviour and sometimes bad stability of AN/GAP formulations. Some of the main features of these propellants have been developed and illustrated in this paper. These are performance, chemical stability, combustion behaviour and detonation sensitivity. Four different kinds of pure and phase stabilized ammonium nitrates are compared regarding stability and combustion behaviour in propellant formulations with GAP and nitrate ester plasticizers. Satisfying solutions have been found for combustion behaviour and stability of AN/GAP-propellants, if pure AN, atomized from the melt and new molybdenum oxide/vanadium oxide burning modifiers are successfully applied.     

Burning Characteristics of Ammonium Nitrate‐based Composite Propellants Supplemented with MnO2

Ammonium nitrate (AN)‐based composite propellants have several major problems, namely, a low burning rate, poor ignitability, low energy, and high hygroscopicity. The addition of a burning catalyst proved to be effective in improving the burning characteristics of AN‐based propellants. In this study, the burning characteristics of AN‐based propellants supplemented with MnO₂ as a burning catalyst were investigated. The addition of MnO₂ is known to improve the ignitability at low pressure. The most effective amount of MnO₂ added (ξ) for increasing the burning rate is found to be 4 %. The increasing ratio with ξ is virtually independent of the burning pressure and the AN content. However, the pressure exponent unfortunately increased by addition of MnO₂. The apparent activation energy of the thermal decomposition for AN and the propellant is decreased by addition of MnO₂. From thermal decomposition kinetics it was found that MnO₂ could accelerate the thermal decomposition reaction of AN in the condensed phase, and therefore, the burning characteristics of the AN‐based propellant are improved.