Dielectric relaxation studies on polymeric salts: Poly(methylmethacrylate-co-N,N-dimethylaminopropyl-acrylamide) benzoic acid systems

A series of polymeric salts of p-substituted benzoic acids in poly(methylmethacrylate-co-N,N-dimethylaminopropylacrylamide) were prepared and AC impedance studies of film-attached electrodes were carried out. The impedance curves and conductivity variation with temperature were analysed. The parameter which describes the shape of the circular arcs in the impedance curves was temperature independent, and the distribution of relaxation times remained constant during the test on the material. Furthermore, the ionic conductivity was highly dependent on the chemical structure produced by the substituted benzoic group.     

4-羟基-3,5-二硝基吡啶铅盐在固体推进剂燃烧中的催化作用

在298.15 K下用精密转动弹热量计测得4-羟基-3,5-二硝基吡啶铅盐(4HDNPPb)的燃烧能ΔcU为(-7385.82±3.14)J.g-1;据此计算的标准摩尔燃烧焓ΔcΗmθ为(-4499.63±1.92)kJ.mol-1,标准摩尔生成焓ΔfΗmθ为(-796.65±2.32)kJ.mol-1。研究了4HDNPPb和含能铜盐(或惰性铜盐)的混合物在RDX-CMDB推进剂燃烧中的催化作用,结果表明,复合催化剂体系:2.5%4-羟基-3,5-二硝基吡啶铅盐(4HDNPPb)与0.5%2-羟基-3,5-二硝基吡啶铜盐(2HDNPCu)的混合物,或2.5%4HDNPPb与0.5%邻苯二甲酸铜(-Cu)的混合物,使RDX-CMDB推进剂的燃烧在所测压力范围内(2~20 MPa)有较高的催化效率,压力指数小于0.3。     

3-氨基-4-氨基肟基呋咱500克级合成

以丙二腈为原料经四步连续反应一锅法合成出了新型含能材料化合物3氨基4氨基肟基呋咱(AAOF),得率达72.4%。用IR、MS、1HNMR、13CNMR、元素分析和紫外特征吸收波长(UV)对其分子结构进行了表征。在优化工艺的基础上实现了AAOF的500g级合成。对AAOF的合成反应历程进行了理论推导和验证。     

3,6-二肼基-1,2,4,5-四嗪及其盐的合成与表征

以三氨基胍盐酸盐和2,4-戊二酮为原材料,通过成环反应,氧化脱氢,肼基取代,三步合成了3,6-二肼基-1,2,4,5-四嗪,同时,对3,6-二肼基-1,2,4,5-四嗪的含能盐的合成进行了研究。对文献报道的反应路线进行了适当的放大研究。通过红外光谱分析、元素分析、质谱分析和1HNMR等方法对产物的结构特征进行了鉴定。     

3,6-二氨基-1,2,4,5-四嗪-1,4-二氧化物的合成放大与性能研究

以3,6-对(3,5-二甲基吡唑)-1,2-二氢-1,2,4,5-四嗪(BDT)为起始物,经两步反应得到了30克级3,6-二氨基-1,2,4,5-四嗪-1,4-二氧化物(DATZO2),总产率46.8%。其中,以用氧气取代氮氧化物为氧化剂获得了合成四嗪类高氮含能材料的重要中间体3,6-对(3,5-二甲基吡唑)-1,2,4,5-四嗪(BT)。对不同合成条件和重结晶条件下获得产物的微观结构进行了表征,并对其感度进行了测试。对产物的热分解性能进行了研究,获得了DATZO2的热分解动力学参数和机理函数。     

TATB原位包覆HMX的研究

为提高TATB对HMX的钝化效果,利用声化学合成方法,在HMX颗粒表面原位生成了TATB,制备了HMX/TATB复合物。并与混合法制备的样品进行了比较。SEM观察表明,原位包覆法TATB对HMX的包覆效果比混合法的包覆效果更好。DSC分析表明,原位包覆法样品中HMX的热分解温度更高。机械感度测试结果表明,在TATB含量相当的情况下,原位包覆法样品具有更低的机械感度,在TATB含量为10%时,撞击感度为24%,摩擦感度为0%。     

离子液体相关电解质研究进展

论述了近年离子液体相关电解质研究进展。利用离子液体或将其与聚合物电解质混合,或与其它电解质盐类混合可制得新型电解质。一些离子液体及相关电解质应用于电池等电化学装置,具有良好的电化学性能,显示了广阔的应用前景。     

Experimental investigation of high-temperature corrosion properties in simulated reducing-sulphidizing atmospheres of the waterwall fireside in the boiler

The presence of reducing atmospheres of the waterwall fireside in the boiler due to extensive use of low-NOx combustion mode caused severe high-temperature corrosion problems. In this study, high-temperature sulphur corrosion properties of two types of low alloyed waterwall steel (15CrMoG and 12Cr1MoVG) in two kinds of reducing-sulphidizing atmospheres were investigated by lab-scale experiments. The experimental atmospheres and temperature were simulated according to field measurements in the boiler of a thermal power plant. The experimental results showed that the reducing-sulphidizing atmosphere with CO was more corrosive, and the CO accelerated the corrosion of H₂S and worsened the corrosion. The CO inhibited the formation of oxide scales, provided some corrosion resistance, and produced the intensely corrosive COS. The corrosivity of the alkali metal chlorides was limited in the reducing-sulphidizing atmosphere without CO, while the corrosion was strongly hindered in the reducing-sulphidizing atmosphere with CO.     

Microtribology,squeeze, and friction of the colloidal layer

Lubricant films containing colloidal overbased calcium salts have particular effects on detergency and on the wear process. The mechanical properties of such boundary films are very dependent on the process conditions, and are essentially a result of physico-chemical transformations of the colloid. Three types of films were compared: a film obtained by the drying of the base solvent, a film due to the compaction of the colloid between two steel surfaces, and a friction film obtained with this type of lubricant. Adsorption, compaction, and shear transformations induce a solid film. The pressure effect on the frictional behaviour of these colloidal films has been investigated using a surface force apparatus for low contact pressure (10⁴ to 10⁶ Pa), and using tribometers supporting heavy loads for the analysis of the high pressure domain. Above a critical pressure, evaluated at 10⁶ Pa, the colloidal film does not flow, but forms a compacted mattress sliding on the surface plane and squeezing a molecular layer of lubricant.     

Nb−Si基超高温合金在900℃下的氧化和热腐蚀行为

对Nb?Si基超高温合金在900℃ 下的氧化和热腐蚀行为进行研究.结果表明:合金的氧化和热腐蚀动力学均由初始的抛物线增长阶段和随后的线性快速增长阶段组成.在氧化的初始阶段(1～50 h),合金表面形成较薄且连续的氧化膜,而在随后的线性阶段,合金表面发生严重的"粉化"现象.合金经热腐蚀后,其线性增长阶段发生得更早,同时在...