Regeneration of Carbonyl Compounds by Oxidative Cleavage of Hydrazones with Zr(O‐t‐Bu)4/tert‐Butyl Hydroperoxide

A catalytic method with Zr(O‐t‐Bu)4 as the catalyst and tert‐butyl hydroperoxide as the oxidant is described to cleave phenylhydrazones 6—9 , 14—16 to the parent carbonyl compounds under mild and neutral oxidative conditions.     

Decomposition of polypropylene hydroperoxides induced by nitric oxide: New concept of reaction mechanism

NO‐induced decomposition of hydroperoxides in solid polypropylene and cumyl hydroperoxide, dissolved in n‐decane, at 25°C was studied. Analysis of kinetic regularities of hydroperoxide decomposition and nitroxide radical accumulation leads to the conclusion that both in solids and in solutions these reactions have the autoaccelerated character. The induction periods are determined by trace amounts of impurities (probably of higher nitrogen oxides).The maximum rate of the process depends on the NO pressure. The possible reaction mechanisms are supposed, and the key role is assigned to the formed nitrosocompounds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 407–414, 2001     

Computer simulation of turbine oil oxidation. 2: Consumption of a hindered phenol antioxidant in laboratory oxidation tests and in service

The computer simulation study of consumption of di-tert-butyl p-cresol (DBPC) was extended to the oxidation of hexadecane/tetralin model oils under conditions of laboratory oxidation tests and in service. The oxidation lives of the model oils in the ALCOA oxidation test and the ASTM D2272 rotary bomb and D943 turbine oil oxidation tests were successfully predicted from the simulation study. The oxidation behaviour of the model oils is compared to that of a turbine oil used in actual service units. The model oil having 6 mass % of tetralin showed almost identical oxidation behaviour to the turbine oil when the same amount of DBPC was added (0.6 mass %). The calculation shows that the direct oxidation of antioxidants is the main process of antioxidant consumption in the laboratory oxidation tests as well as in the model oxidation system without metal catalysts. In most of the service units which operated at moderate conditions the calculation shows that the direct oxidation of antioxidants is also the main, process. As a consequence, the rate of antioxidant consumption does not depend much on the tetralin content in the model oils. The oxidation behaviour of the model oils in the service units which operate under severe conditions, such as in the high temperature regions of turbines, is calculated by setting a flow reactor model. The results of this calculation show in this case that the turbine oil degradation occurs mostly in the high temperature regions and that the rate of antioxidant consumption increases with an increased amount of tetralin in the model oils. This strong dependence on base oil composition can be attributed to the increased importance of antioxidant consumption through the inhibition of oxidation.     

微波协同固体超强酸催化合成香料肉桂酸环己酯

以肉桂酸和环己醇为原料,用微波协同固体超强酸SO2-4/Ti O2/La3+催化合成了肉桂酸环己酯。通过单因素实验和正交实验考察催化剂种类、催化剂用量、肉桂酸与环己醇物质的量比、微波功率、微波时间对肉桂酸环己酯产率的影响。实验结果表明,肉桂酸环己酯最佳合成条件为:催化剂固体超强酸SO2-4/Ti O2/La3+用量为1.0g,肉桂酸与环己醇物质的量比1∶4,微波功率为600W,微波时间为15min,肉桂酸环己酯产率可达到97.5%。该工艺操作简单,反应条件温和,节约时间,产品纯度高,是一种高效环保的合成工艺。      

环己苯对不同锂离子电池过充性能的影响

采用3C/5V和1C/10V过充测试研究了在电解液中添加环己苯(CHB)对不同材料体系锂离子电池防过充性能的影响,考察了CHB的加入对LiCo1/3Ni1/3Mn1/3O2正极材料体系锂离子电池循环性能的影响。结果表明:在LiCoO2正极材料体系锂离子电池中,电解液添加2%(质量分数)的CHB,不能明显提高电池的耐过充性能,而在LiCo1/3Ni1/3Mn1/3O2正极材料体系锂离子电池中,则可以明显提高电池的耐过充性能,同时对电池的循环性能几乎没有影响,循环300周后,容量保持率为91.9%。     

微量Cu2+对过氧化氢异丙苯热稳定性的影响

为研究微量铜离子（Cu2+）对过氧化氢异丙苯（CHP）热分解的影响,采用绝热加速量热仪（ARC）对CHP及含两种不同浓度Cu2+的CHP进行了绝热分解测试,研究了不同浓度Cu2+对CHP起始的分解温度（To）、最高分解温度（Tf）、绝热温升（△Tad）、最大温升速率（mm）等热力学参数及分解活化能（Ea）的影响,并利用热惰性因子（Φ）对实验数据进行了修正。结果表明：微量Cu2+的加入对CHP分解的热力学参数有影响,而且浓度不同影响不同。如CHP的校正起始分解温度（To,s）和Ea分别为111.28 ℃和170.93 kJ/mol,而加入（1.85×10-3）%或（3.70×10-3）% Cu2+后,相应的参数分别为104.26 ℃、164.73 kJ/mol和98.87 ℃、145.63 kJ/mol。表明微量Cu2+的存在能降低CHP的起始分解温度To,s和活化能Ea,且浓度越高,降低越明显,从而增加了CHP的热分解风险。     

Researches on improving the quality and quantity of the feed for catalytic cracking

Studies have been carried out on the influence of cumene hydroxperoxide at high temperatures on the properties of the atmospheric residue of crude oil and on the composition and quantity of the fraction obtained at 350–490 °C during its vacuum distillation. This treatment results in an increase in the yield of the fraction boiling at 350–490 °C and a decrease in coke and heavy metals contents.     

异丙苯法制苯酚氧化工艺的研究进展

介绍了目前生产苯酚的异丙苯法,并针对异丙苯法制苯酚氧化工艺中存在的缺陷,概述了反应机理及动力学模型,对各种氧化工艺措施改进的研究现状进行了归纳总结,指出开发绿色高效的催化剂体系以及通过改进或改变反应器形式来提高异丙苯氧化效率,是异丙苯制苯酚氧化工艺主要发展方向,对优化异丙苯氧化工艺具有十分重要的意义。     

锂离子电池耐过充添加剂的研究

环己基苯和二甲苯作为耐过充添加剂加入锂离子电池电解液中。环己基苯和二甲苯分别在4.70 V、4.66 V(vs.Li/Li )处发生电聚合反应。聚合物几乎全部覆盖在隔膜表面,阻断了反应,改善了电池的安全性。添加5%添加剂的电池,均可耐3C1、0 V过充电,且对电池正常充放电时的电化学性能影响很小。     

Determination of lipid and protein hydroperoxides using the fluorescent probe diphenyl-1-pyrenylphosphine

By means of two alternative methods lipid and protein hydroperoxides (HP) were determined by fluorometry using the diphenyl-1-pyrenylphosphine (DPPP) probe. It has been shown that the formation of the fluorescence was influenced by the type of solvent and HP whereas the presence in the media of antioxidants such tocopherol and butylated hydroxytoluene had no effect. The combination of the chloroform:methanol (2:1, v/v) solvent mixture that is widely used for lipid extraction was combined with suitable solvents to develop a method with the maximum performance in determining HP in lipid extracts. Using a variety of lipids and lipid extracts, the final method proposed agreed well with the thiocyanate method for HP determination. In addition, the DPPP method was very sensitive, precise, accurate, free of interferences and specific for the determination of lipid soluble HP. DPPP can be also used to measure HP soluble in hydroalcoholic media. This alternative procedure showed a similar performance to its lipid soluble equivalent and was able to measure hydrogen peroxide promoted peroxidation of bovine serum albumin and water soluble HP in protein extracts. With the addition of triphenylphosphine the hydroalcoholic method is specific for the determination of protein HP.