RDX在68%硝酸中溶解度的测定及关联

采用测定固体在液体中溶解度的实验装置,用静态平衡法测定298 K～343 K时黑索今（RDX）在质量分数68%硝酸中的溶解度。用数学方法对RDX在不同温度下溶解度数据进行关联,拟合出RDX溶解度与温度的线性方程,并计算不同温度下RDX在68%硝酸中的溶解度。与实测溶解度值进行比较,平均相对误差小于2%。建立了溶解-结晶模型并界定介稳区宽度,从而为RDX在不同温度下重结晶提供了参数依据。     

HMX溶解度的测定及关联

采用测定固体在液体中溶解度的实验装置,用静态平衡法测定20—90℃时,奥克托今（HMX）在二甲基亚砜、68％硝酸中的溶解度及20—55℃时在丙酮中的溶解度。采用数学方程对HMX的溶解度数据进行关联,拟合出了HMX溶解度的对数与绝对温度倒数的一元线性方程,可用于估算HMX在不同温度下的溶解度,平均相对误差均小于0．5％,为HMX在不同温度下重结晶提纯和细化提供参数依据。     

阿魏酸和川芎嗪在超临界CO2中溶解度的测定

采用动态法分别测定了阿魏酸和川芎嗪在超临界CO2中的溶解度.实验结果表明在压力10～35MPa和温度308.15～338.15K范围内,阿魏酸在超临界CO2中的溶解度(摩尔分数)为6.936×10(7～26.527×10(7;在压力10～30MPa和温度318.15～338.15K范围内,川芎嗪在超临界CO2中的溶解度(摩尔分数)为0.010～0.131.阿魏酸在超临界CO2中的溶解度随着压力的增加而增大;温度对阿魏酸溶解度的影响较为复杂,出现了交迭压力行为.而川芎嗪在超临界CO2中的溶解度在实验范围内没有出现交迭压力行为.采用Chrastil方程分别对阿魏酸和川芎嗪在超临界CO2中的溶解度数据进行了关联,其AARD值分别为12.92%和4.23%.     

CO2在二甲基亚砜中溶解度的测定及其亨利常数

为了验证烟气吸收剂二甲基亚砜(DMSO)对SO2和CO2的选择性能,在常压吸收装置中,实验测定了不同浓度CO2在DMSO中的溶解度.实验温度293.15～313.15 K,CO2的分压5.56～18.2 kPa.结果表明,二氧化碳在二甲基亚砜中有较小的溶解度.在实验浓度范围内,二氧化碳在DMSO溶剂中的溶解过程符合亨利定律.在测得的实验数据基础上,得到了CO2在DMSO中的亨利常数值.由实验数据可得出结论,DMSO对SO2和CO2有良好的选择性,用于烟气脱硫是可行的.     

喜树碱在二甲亚砜和甲醇(或乙醇)混合溶剂中溶解度的测定和关联

采用重量法测定了喜树碱(camptothecine,CPT)在二甲亚砜(dimethylsulfoxide,DMSO)+甲醇(或乙醇)混合溶剂中的溶解度,温度范围是274.50~326.00 K。在混合溶剂中CPT的溶解度随温度的升高而增大,随混合溶剂中DMSO摩尔分数含量的增大而增大。分别用修正Apelblat方程、λh方程和理想状态方程进行关联,关联效果令人满意,获得了相关模型参数。相对而言,λh方程关联的效果较好。根据溶解度数据和修正的Apelblat方程计算出溶解焓、溶解熵和吉布斯自由能。     

CO_2在正戊醇中的溶解度和体积传质系数

基于等体积饱和法搭建了气体在液体中溶解度与体积传质系数的实验测量系统,该实验系统温度、压力、溶解度、体积传质系数的扩展不确定度分别为0.02 K、0.01%、2%、4%。利用该实验系统测量了温度为323～343K、压力为0.9～5.0 MPa范围内CO_2在正戊醇中的溶解度和体积传质系数。CO_2在正戊醇中的摩尔分数随着压力的升高而升高,在温度为323 K时,压力从2.5 MPa升高到3.2 MPa,溶解度升高26%。CO_2在正戊醇中的摩尔分数随着温度的升高而减小,在压力为0.9 MPa时,温度从323 K升高为343 K,溶解度降低26%。升高温度和压力都有利于提高体积传质系数,当温度和初始压力分别由323 K、1.1 MPa升高至343 K、5.0 MPa时,CO_2在正戊醇中的体积传质系数由0.0089 s~(-1)升高至0.0175 s~(-1)。     

粒度和温度对HMX溶解度的影响

采用饱和溶液-溶剂蒸发法在5、20、40和60℃条件下测试了平均粒度为80μm、5μm、500nm和100nm的HMX在不同溶剂中的溶解度。结合相似相溶原理和分子热运动分析了溶解度变化原因。结果表明,HMX在去离子水中基本不溶,在低级醇中的溶解度大于高级醇中的溶解度,在乙酸乙酯中的溶解度较大,随着温度升高,相同粒度HMX的溶解度增大;在同一温度下,随着粒度的减小,HMX溶解度增大。     

CO2在正戊醇中的溶解度和体积传质系数

基于等体积饱和法搭建了气体在液体中溶解度与体积传质系数的实验测量系统,该实验系统温度、压力、溶解度、体积传质系数的扩展不确定度分别为0.02 K、0.01%、2%、4%。利用该实验系统测量了温度为323～343 K、压力为0.9～5.0 MPa范围内CO₂在正戊醇中的溶解度和体积传质系数。CO₂在正戊醇中的摩尔分数随着压力的升高而升高,在温度为323 K时,压力从2.5 MPa升高到3.2 MPa,溶解度升高26%。CO₂在正戊醇中的摩尔分数随着温度的升高而减小,在压力为0.9 MPa时,温度从323 K升高为343 K,溶解度降低26%。升高温度和压力都有利于提高体积传质系数,当温度和初始压力分别由323 K、1.1 MPa升高至343 K、5.0 MPa时,CO₂在正戊醇中的体积传质系数由0.0089 s^-1升高至 0.0175 s^-1。     

高温下对苯二甲酸在醋酸-水溶液中的溶解度预测

在醋酸摩尔分数0.73,温度130～270℃的范围内利用UNIFAC模型估算了对苯二甲酸在醋酸 水溶液中的溶解度,估算值与文献值的平均相对误差7.74%,表明本文所建方法在缺乏实验数据的情况下可以用来预测高温下TA在醋酸 水溶液中的溶解度。因此,用该方法预测了130～270℃范围内60%～90%醋酸 水溶液中的TA的溶解度,给出了不同组成下的溶解度 温度图。     

乙醇-水溶剂中5'-尿苷酸二钠溶解度测定与关联

采用内置双光路激光检测器,在293.2-318.2 K温度范围内,测定了5'-尿苷酸二钠在纯水及不同乙醇-水混合溶剂中的溶解度.分别用R-K方程、λh方程和Wilson方程3种溶解度模型,采用最小二乘法关联实验数据,并对比不同溶解度模型.结果表明,在乙醇质量分数为0-0.65区间内,5'-尿苷酸二钠溶解度随着温度的升高而增大,随乙醇质量分数的增大而显著减小,λh方程对5'-尿苷酸二钠溶解度关联效果最好.将λ,h表达为乙醇质量分数的函数,并用于内插计算,精度满足工程要求.     

剑麻皂甙元在甲醇和乙醇中溶解度的测定及应用

常压下,平衡法测定了剑麻皂甙元在甲醇(293~338K)和乙醇(293~353K)溶剂中的溶解度,并对溶解度数据进行关联拟合。结果表明:剑麻皂甙元在两种溶剂中的溶解度均随温度的升高而增大。温度293~323K时,甲醇溶解度高于乙醇溶解度,温度大于323K时,乙醇溶解度高于甲醇溶解度。甲醇和乙醇拟合方程校正决定系数分别为0.9961和0.9976,温度318~338K时,甲醇平均相对误差2.12%,温度328~353K时,乙醇平均相对误差2.56%,拟合方程基本可满足工程设计需要。对两种溶剂在剑麻皂甙元工业生产中的应用进行了研究,表明乙醇作为剑麻皂甙元的萃取溶剂优于甲醇。     

Nano Cyclotetramethylene Tetranitramine Particles Prepared by a Green Recrystallization Process

The solubility of cyclotetramethylene tetranitramine (HMX) in four ionic liquids (ILs): 1,3‐dimethylimidazolium dimethylphosphate ([Memim]DMP), 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl), 1‐hexyl‐3‐methylimidazolium bromide ([Hmim]Br), and 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([Emim]BF₄) was investigated. Nano‐HMX were produced particles by spraying [Hmim]Br solution into purified ice water. Finally, the particle size, morphology, crystal phase, impact sensitivity, and thermal decomposition properties of nano‐HMX particles were tested and analyzed. All four ILs could dissolve HMX to a greater or lesser extent in the temperature range from 20 °C to 80 °C. The solubility of HMX in [Hmim]Br at 80 °C is up to 0.7 g mL⁻¹. Recrystallized HMX particles are of polyhedral or spherical shape and 40 to 130 nm in size. X‐ray diffraction indicated that nano‐HMX has a similar crystal structure as raw HMX (β‐form). Compared with raw HMX, the nano‐HMX particles have much lower impact sensitivity. However, they are easier to explode than raw HMX under thermal stimulus due to the lower peak temperature and activation energy.     

超(近)临界水氧化法降解炸药废水的工艺优化与动力学研究

炸药工业排放废水中含TNT、RDX、HMX等多种剧毒物质,一般难以生物降解甚至不可生物降解,处理非常困难.并且炸药废水的COD很大,对水体污染严重.文中采用超(近)临界水氧化技术,对TNT, RDX和HMX模拟炸药废水进行正交实验及反应动力学研究,在降解TNT, RDX和HMX同时降低废水的COD值.得到最佳氧化降解工艺条件为:反应温度648 K,反应时间5 min,模拟炸药废水:氧化剂(H_2O_2) (体积比)= 10:1,处理后废水的COD=38 mg·L~(-1),COD降解率为98.65%.动力学研究结果表明,在573 K、603 K、623 K、653 K时的表观速度常数k分别为:0.01030、0.02069、0.03709和0.04699.TNT、RDX、HMX氧化反应的活化能、指前因子和平均反应级数分别为:61.31 kJ·mol~(-1),4251,1.56.     

Solubility of CO in solid-state PET measured by pressure-decay method

The solubility of CO₂ in solid-state PET was measured using a pressure-decay method. In order to calculate the solubility of CO₂ in the amorphous region of PET, the crystallinity of solid state PET dissolved in CO₂ at different pressures and temperatures was measured by differential scanning calorimetry (DSC). The solubility increases with increasing pressure and it follows a linear relationship and obeys Henry’s law when the pressure is below 8 MPa. The effect of temperature on solubility is weak and the solubilities at different temperatures are almost the same under low pressures. At higher pressure, the solubility decreases with an increase in temperature. The solubility of CO₂ in the amorphous region of PET at 373.15 K, 398.15 K and 423.15 K was correlated with the Sanchez-Lacombe equation of state with a maximal correlation error of 6.69%.     

Thermal expansion,transitions, sensitivities and burning rates of HMX

The phases of HMX and their transitions were investigated by thermal analysis using X-ray diffraction. Series of diffraction pattern were measured, while the samples were heated and cooled. The thermal expansion coefficients and the colume changes at the transitions were extracted from the diffraction series. A contraction of β-HMX was found before changing into δ-HMX resulting in a high volume difference during the transition. On cooling, the reconversion of the high temperature phase requires days. It is further slowed down by decomposition products, which are formed at temperatures beyond 490 K. The final reconversion results in mixtures of α-and βHMX. The mechanical sensitivities and the buring rates of the HMX phase were determined. The high sensitivity of δ-HMX against impact together with its slow reconversion creates handling risks when the HMX is exposed to temperatures above 440 K.     

HMX/SiO2凝胶的制备及表征

基于溶胶-凝胶工艺,在二氧化硅(SiO2)溶胶向凝胶的相变作用过程,在凝胶点时加入HMX的二甲亚砜(DMSO)溶液,制备出HMX/SiO2(质量比80∶20)凝胶。用扫描电镜和傅里叶变换红外光谱对产物进行表征。结果表明,HMX/SiO2凝胶呈近似直径为0.5～1.0μm球形。与相同质量分数的HMX/SiO2机械掺杂混合物相比,HMX/SiO2凝胶的特性落高H50由31.70cm提高至52.24cm,摩擦感度由30%降至0。在铜管约束条件下,当平均装药的密度为1.15g/cm3时,临界传爆直径约为0.6mm。     

CO_2在碳酸二甲酯中的溶解度及强化途径

采用恒定容积法测定了283.15—303.15 K CO2在碳酸二甲酯(DMC)中的溶解度。结果表明,溶解度随压力升高而增大,随温度升高而减小。与碳酸丙烯酯(PC)相比,在283.15 K及288.15 K条件下,CO2在DMC中的溶解度比在PC中平均约高50%。并且常温下DMC的吸收性能优于低温下甲醇的吸收性能。因此,DMC是一种性能更为优越的溶剂。加入1.5 g金属-有机骨架化合物(MOF)ZIF-69后,温度为283.15 K及288.15 K时对DMC吸收CO2具有增强作用,而在295.15 K及303.15 K时无影响。这种特性也有利于CO2吸收和解吸循环过程的节能。     

Generation of Free Radicals in RDX and HMX Compositions

Efforts to generate detectable concentrations of free radicals in explosives, binders, and their mixtures are described. Radicals were readily produced in polycaprolactone and polyethylene glycol binders at liquid nitrogen temperature using stresses as low as 0.4 kbar. These radicals were all of the peroxy type, and presumably formed by reaction of mechano-radicals with oxygen present in the polymer. No mechano-radicals were observed from HMX or RDX using samples cooled to liquid nitrogen temperature and applied stresses up to 4 kbar. In neither impacted samples that failed to explode nor the residues remaining after a partial explosion were radicals detected by ESR. Low temperature γ-irradiation of these materials was also carried out. Free radical signals originating in both the polymer and the explosive could be identified. The reactivity of NO₂ radicals from γ-irradiated HMX is enhanced in the presence of binder. In γ-irradiated HMX/polycaprolactone mixtures, the NO₂ radical anneals rapidly at 150 K, versus 240 K for HMX alone. Evidence is presented to suggest that the relatively stable NO₂ radical (such as produced by γ-irradiation) in HMX does not play a dominant role in mechanical initiation.