离子液体协同催化合成游离氨基酸酯

以L-氨基酸和醇为原料,酸性离子液体辅以少量强酸性阳离子交换树脂作催化剂,直接酯化合成了8种游离的L-氨基酸酯,并用1HNMR对产物进行了表征。通过L-苯丙氨酸正丁酯的合成对离子液体的活性进行了考察,结果表明,所选用的11种离子液体在反应过程中均起到了一定的催化作用和助溶作用。其中,[Hmim][HSO4]效果较好,在重复使用后,显示了较好的稳定性,是氨基酸酯化反应理想的催化剂和助溶剂。     

酸性镀铜工艺硫酸过量引起的故障分析

工业生产中,硫酸的过量添加会造成酸性镀铜工艺阳极钝化、槽电压升高、工作电流下降.本文讨论了硫酸对硫酸铜溶解度的影响,发现水溶液中硫酸含量超过50 g/L后硫酸铜的溶解度急剧下降.当硫酸含量过高时,随着电镀过程的进行,CU<'2+>在阳极表面层的浓度不断升高,引起硫酸铜晶体在阳极表面析出,使阳极钝化,导致无法正常生产.     

磺酸功能化离子液体催化不饱和脂肪酸甲酯的环氧化研究

The epoxidation of unsaturated fatty acid methyl esters(FAMEs)by peroxyacetic acid generated in situ from hydrogen peroxide and acetic acid was studied in the presence of SO3H-functional Brnsted acidic ionic liquid (IL)[C3SO3HMIM][HSO4]as catalyst.The effects of hydrogen peroxide/ethylenic unsaturation ratio,acetic acid concentration,IL concentration,recycling of the IL catalyst,and temperature on the conversion to oxirane were studied.The kinetics and thermodynamics of unsaturated FAMEs epoxidation and the kinetics of oxirane cleavage of the epoxidized FAMEs by acetic acid were also studied.The conversion of ethylenic unsaturation group to oxirane, the reaction rate of the conversion to oxirane,and the rate of hydrolysis(oxirane cleavage)were higher by using the IL catalyst.     

强酸性阳离子交换树脂催化合成对甲氧基苯乙酮环乙二缩酮

以强酸性阳离子交换树脂为催化剂,对甲氧基苯乙酮和乙二醇为原料合成了对甲氧基苯乙酮环乙二缩酮,并考察了带水剂种类及用量、原料配比、催化剂用量、反应时间、催化剂重复使用等因素对反应的影响。结果表明,较佳工艺条件为:n(对甲氧基苯乙酮)∶n(乙二醇)=1∶1.3,带水剂环己烷的用量为40 mL,强酸性阳离子交换树脂用量为1.5 g(相对于0.1 mol对甲氧基苯乙酮),反应时间为3 h;产物收率95.58%,产品纯度w>99.0%;催化剂不经处理可以循环使用不少于5次。     

添加剂对酸性镀铜耐蚀性的研究

研究了酸性镀铜工艺中两种添加剂的质量浓度对铜镀层的影响.实验通过塔菲尔方程测定了在不同镀液中所得镀层的耐蚀性能,并研究了PEG和C1-共同存在时对镀层耐蚀性能的影响.通过实验总结出了PEG和C1-之间在一定的质量浓度下的协同规律和最佳比例.     

铜粉处理酸性镀铜溶液中氯离子的机理

阐明了用铜粉处理酸性镀铜溶液中氯离子的机理,理论分析和实验表明,在酸性镀铜溶液中,Cu2+离子与铜粉反应生成Cu+离子,同时氯离子与Cu+离子反应生成氯化亚铜沉淀.向镀液中加铜粉1g/L,氯离子的起始质量浓度为174mg/L时,氯离子的去除率为58.9%,而向镀液中加锌粉1g/L,氯离子的去除率为47.0%,用铜粉处理...     

异山梨醇的制备及应用研究进展

介绍了异山梨醇的来源、用途和制备方法,阐述了由山梨醇脱水制备异山梨醇的催化剂及研究进展。异山梨醇在食品、化妆品、医药、塑料及聚合物等领域有广泛的应用,被誉为未来重要的生物基化工原料,因此深入开展以山梨醇为原料脱水制备异山梨醇的研究具有重要意义。     

铅酸蓄电池矿灯发展之路

铅酸蓄电池矿灯目前已经处于生存的关键点.锂电池矿灯现在已占领市场90％以上,如果酸性矿灯企业或者酸性矿灯蓄电池企业不投入足够的精力,给予足够的重视,可能濒临淘汰.减重量,增容量,稳质量是酸性矿灯立足市场的唯一选择.     

Beyond Yield Optimization: The Impact of Organosolv Process Parameters on Lignin Structure

When optimizing the process parameters of the acidic ethanolic organosolv process, the aim is usually to maximize the delignification and/or lignin purity. However, process parameters such as temperature, time, ethanol and catalyst concentration, respectively, can also be used to vary the structural properties of the obtained organosolv lignin, including the molecular weight and the ratio of aliphatic versus phenolic hydroxyl groups, among others. This review particularly focuses on these influencing factors and establishes a trend analysis between the variation of the process parameters and the effect on lignin structure. Especially when larger data sets are available, as for process temperature and time, correlations between the distribution of depolymerization and condensation reactions are found, which allow direct conclusions on the proportion of lignin's structural features, independent of the diversity of the biomass used. The newfound insights gained from this review can be used to tailor organosolv lignins isolated for a specific application.     

2,6-二乙酰氨基吡嗪-1-氧化物硝化反应研究

研究了2,6-二乙酰氨基吡嗪-1-氧化物在硝硫混酸和发烟硝酸/酸性离子液体中的硝化反应。在混酸硝化体系中,考察了混酸硝化剂类型对产物2,6-二氨基-3,5-二硝基吡嗪-1-氧化物(LLM-105)收率和纯度的影响。在发烟硝酸/N,N,N-三甲基-N-丙磺酸基-硫酸氢铵(TMPSHSO4)硝化体系中,考察了在酸性离子液体催化条件下酸性离子液体使用量、硝解反应温度、酸性离子液体重复使用次数对LLM-105收率和纯度的影响。结果表明:混酸硝化体系中,2,6-二乙酰氨基吡嗪-1-氧化物的最佳硝化剂为KNO3和质量分数20%发烟硫酸,LLM-105的收率为72.5%,质量分数为98.6%。发烟硝酸/酸性离子液体硝化体系中,最佳反应条件为:TMPSHSO4与2,6-二乙酰氨基吡嗪-1-氧化物的物质的量的比为0.051.00,硝解温度为75℃,LLM-105收率为64.8%,质量分数为98.5%,TMPSHSO4经回收可重复使用3次。相对而言,以发烟硝酸/TMPSHSO4为硝化剂合成LLM-105更具优势。用1H NMR、IR和MS对LLM-105的结构进行了表征。