N-苯基邻苯二甲酰亚胺在离子液体中的合成

研究了以1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)为反应溶剂进行N-苯基邻苯二甲酰亚胺的合成方法,通过改变反应时间和温度以及反应物配比等条件,确定了反应的较优条件.以[bmim]BF4为反应溶剂,苯胺和苯酐物质的量配比为1.2,在110 ℃下反应2 h的产率可达94%.该法能简化产物分离,实现了N-苯基邻苯二甲酰亚胺的高效绿色合成.     

[bmim]PF_6增塑PVC糊树脂膜迁移规律研究

文章应用固相萃取、液相色谱联用技术,研究了[bmim]PF6增塑PVC糊树脂膜中的[bmim]PF6在水环境及低酒精含量模拟溶剂（15%乙醇-水溶液）中的迁移规律,同时研究了[bmim]PF6迁移对薄膜力学性能的影响。结果表明：时间和温度对[bmim]PF6向水环境中迁移均有加速效应,在中性条件下迁移量较小,在酸性和碱性条件下迁移量较大。[bmim]PF6在低酒精含量模拟溶剂中与浸泡在去离子水中的薄膜迁移量相比,迁移量明显降低。增塑剂迁出后PVC糊树脂膜的断裂伸长率降低,弹性模量、拉伸强度均升高,可望用于医疗制品的开。     

烃基咪唑和吡啶鎓氢氧化物碱性离子液体的合成

以KOH或NaOH作碱试剂,考察了溶剂对1-丁基-3-甲基咪唑溴鎓([bmim]Br)合成1-丁基-3-甲基咪唑鎓氢氧化物([bmim]OH)碱性离子液体的影响,并采用强碱性阴离子交换树脂法合成[bmim]OH.结果表明:在室温下,溶剂10mL,[bmim]Br和KOH的物质的量之比为1:1.1的条件下,以乙醇为溶剂反...     

1-丁基-3-甲基咪唑四氟硼酸盐离子液体的合成与表征

以N-甲基咪唑和1-溴代正丁烷为原料,两步合成法制备了离子液体[bmim]BF4。考察了反应时间、反应温度、原料配比对中间体1-丁基-3-甲基咪唑溴盐[bmim]Br收率的影响和离子交换时间和离子交换温度对目标产物[bmim]BF4产率的影响。结果表明:①合成中间体[bmim]Br的最佳条件为:反应温度65℃,反应时间16 h,N-甲基咪唑与1-溴代正丁烷的摩尔比为1∶1.1,产品收率可达94.8%;②合成离子液体的最佳条件为:反应温度65℃,反应时间24 h。     

基于绿色催化体系的聚乳酸合成及其热降解性能分析

分别以纳米氧化锌(nano-ZnO)和离子液体[bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐)为催化剂、L-乳酸为单体,采用直接缩聚法合成了聚乳酸(PLA),并优化了工艺条件。结果表明:最佳工艺条件为催化剂用量0.5%、反应时间14 h、反应温度170℃。另外,GPC、FTIR、~1H-NMR和XRD等分析测试结果表明:两种催化剂合成的PLA分子量分别为13 072和6 871 g/mol,且具有相同的晶型(α晶型)。在此基础上,采用热重法研究了PLA的热降解性能。研究表明:以[bmim]PF_6为催化剂合成的PLA,其热稳定性远高于以nano-ZnO为催化剂合成的PLA。     

疏水性咪唑类离子液体的水浴微波合成

以溴代烷烃、N-甲基咪唑和六氟磷酸铵为原料,采用水浴微波法合成了3种疏水性咪唑类离子液体:[bmim]PF6、[hmim]PF6和[omim]PF6.结果表明,与传统方法相比,水浴微波法产率较高,且反应时间由传统的36 h缩短至50 min.通过正交试验对离子液体[bmim]PF6的水浴微波合成反应条件进行了优化,得到了适宜的合成条件:反应时间50 min,n(1-溴正丁烷)∶n(N-甲基咪唑)∶n(六氟磷酸铵)为1.1∶1.0∶1.0,微波功率385 W,产率可达到94.54%.结合反应机理对优化结果进行了分析,并通过红外光谱验证了3种疏水性离子液体的结构.     

1-丁基-3-甲基咪唑六氟磷酸盐离子液体合成

按照两步法合成了离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6),探讨了时间、温度、溶剂、反应物配比等对中间体1-丁基-3-甲基咪唑溴盐([Bmim]Br)以及离子液体[Bmim]PF6产率的影响。结果表明,反应物配比为(1∶1.1)~(1∶2),温度70℃,反应30 h,中间体产率为95.91%;中间体中加入等摩尔KPF6,25℃下反应10 h后,离子液体产率为97.26%。     

微波法制备咪唑类离子液体

运用常规两步法和微波法制备了离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)以及1-羟乙基-3-甲基咪唑四氟硼酸盐([C2OHmim]BF4),并通过红外光谱表征以及密度和溶解度等物理性质的检测,对两种制备方法进行了比较。实验结果表明,不需使用任何溶剂,选择N-甲基咪唑和溴代正丁烷(2-氯乙醇)的配比为1∶1.1,[bmim]Br([C2OHmim]Cl)和NaBF4的配比为1∶1,在微波炉功率为350 W的条件下反应,[bmim]BF4和[C2OHmim]BF4的产率分别达70.0%和76.9%。反应采取微波间歇加热的方式,方法简单高效、无溶剂污染,但产率偏低,其制备条件还需进一步研究与完善。     

咪唑离子液体为溶剂合成β-四硝基酞菁锌

以4-硝基邻苯二腈、二水醋酸锌为原料,离子液体[bmim]BF4为溶剂,一步反应合成β-四硝基酞菁锌。通过IR光谱、UV-Vis光谱表征了其结构,采用单因素实验对影响β-四硝基酞菁锌收率的主要因素进行了考察。结果表明:反应温度140℃,反应时间4h,m([bmim]BF4)/m(4-硝基邻苯二腈)=10:1为最佳条件。采用本法合成金属酞菁,反应条件易控、无需回流、简化了实验过程,提高了合成效率。     

离子液体[bmim]PF_6对聚乳酸的增塑作用

合成了离子液体[bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐),并对其进行了表征。用TG、DSC和偏光显微镜等手段研究了[bmim]PF6对聚乳酸的增塑作用,并比较了它与聚乙二醇300(PEG300)的增塑效果。热重分析结果表明,PEG300作增塑剂时,由于其热降解温度较低,聚乳酸热稳定性变差;离子液体[bmim]PF6作增塑剂时,由于其热失重温度高于聚乳酸热降解温度,用其增塑的聚乳酸热稳定性变好。当[bmim]PF6的质量分数从2%增加到10%时,聚乳酸材料的玻璃化转变温度(Tg)随之降低,当加入质量分数为10%的[bmim]PF6时,聚乳酸材料的Tg降至40℃。偏光显微镜观察看出,加入[bmim]PF6后聚乳酸分子链段的活动能力增强,促进了聚乳酸的结晶,且随其用量增加,结晶度增加。该文报道工作的新颖性,已为教育部科技查新工作站(Z12)于2008年2月26日出具的第ZDT2008017号《科技查新报告》所证实。     

1,2,3-三甲氧基苯的绿色合成工艺研究

采用碳酸二甲酯(DMC)代替传统的有毒有害试剂作为甲基化试剂和以廉价的焦性没食子酸(PA)为原料,在离子液体[ Bmim] Br催化作用下合成1,2,3-三甲氧基苯(TMB).通过单因素和正交试验考察了PA和DMC的摩尔比、催化剂的用量、反应温度以及反应时间等因素对甲基化反应的影响.结果表明:各因素的影响程度为反应温度...     

过氧化尿素的合成及分析方法的研究

以30%H2O2和尿素为原料制备过氧化尿素,考查了H2O2与尿素的摩尔比、反应温度、反应时间、结晶时间、干燥温度与时间等因素对产物H2O2含量的影响。结果表明,合成过氧化尿素的适宜条件为:H2O2与尿素的摩尔比为1∶1.1,反应温度为30℃、反应时间为30 m in,在-5℃结晶30 m in,52~55℃干燥2 h,其H2O2的含量可达35%以上。对过氧化尿素的分析方法进行了探讨,通过对高锰酸钾法和碘量法的精密度以及准确度比较,得出高锰酸钾法更为准确。50℃储存24 h,其分解率仅为0.17%,说明过氧化尿素比较稳定。     

硝基苯对傅克酰基化反应制备羧基化聚苯乙烯的影响

在常用的傅克反应溶剂二氯甲烷中添加另一种傅克反应溶剂硝基苯,且酰基化试剂邻苯二甲酸酐(PA)与硝基苯的摩尔比为1时,可大大提高PA的转化率.研究发现,作为傅克酰基化反应的常用溶剂,二氯甲烷和硝基苯的作用是不同的,硝基苯可能参与了傅克酰基化反应的中间过程;研究还发现,硝基苯的加料方式对反应结果的影响,与PA与硝基苯的摩尔比例有关.通过傅克酰基化反应制备了羧基化交联聚苯乙烯微球.     

影响十二烷基多糖苷的合成因素研究

采用交换法合成十二烷基葡萄糖苷,考察了催化剂、醇糖比、反应时间、反应温度及脱醇工艺等对反应结果的影响。结果表明,优惠工艺条件是:反应温度为110℃左右催化剂/葡萄糖摩尔比为0 01∶1、正丁醇/葡萄糖摩尔比为5∶1、十二醇/葡萄糖摩尔比为6∶1的条件下反应,经柱层析去除残留正十二醇,十二烷基多糖甙收率为85 5%,并测定了产品的表面张力和起泡性能。     

固体酸催化剂反应精馏法合成乙酸正丙酯的研究

研究了以阳离子交换树脂作为催化剂进行反应精馏合成乙酸正丙酯,分别考察了不同回流比、酸醇摩尔比以及不同固体酸催化剂类型对酯化反应的影响,并结合工艺条件进行催化剂的筛选,确定反应的较佳工艺条件。实验结果表明,回流比为1∶2,酸醇摩尔比为1∶2,乙酸正丙酯的收率为51.49%。     

Esterification of ethanol with sulfuric acid: A kinetic study

Experiments were conducted in a stirred batch reactor under isothermal conditions for obtaining kinetics of the esterification reaction between ethanol and sulfuric acid. Reactive adsorption technique was employed to enhance the conversion. Anhydrous sodium sulfate was used as an adsorbing agent to remove the water formed during the reaction. The variables include the mole ratio of ethanol to sulfuric acid, reaction temperature, purity of the reactants, and the amount of adsorbing agent. The reaction was found to be reversible and second order at low mole ratios, and irreversible and first order at high mole ratios. The kinetic parameters of the rate law were estimated. A possible reaction mechanism was proposed and validated with the experimental data. The effect of the mole ratio of reactants, anhydrous sodium sulfate loading, and purity of the reactants on the yield of ethyl hydrogen sulfate was studied, using full‐factorial search and optimized conditions were obtained by the method of steepest ascent. More precise optimum conditions were obtained using the Box‐Wilson composite method.     

Direct synthesis of benzyl acetate and optimisation of reaction conditions for the gas phase acetoxylation of toluene

TiO₂ supported Pd-Sb catalysts were prepared by impregnation method and tested for the selective vapour phase acetoxylation of toluene to benzyl acetate (BA). Investigations were carried out to optimise reaction variables such as effects of reaction temperature, acetic acid/toluene mole ratio, O₂/toluene mole ratio, contact time, etc. to obtain better performance of the catalysts. Additionally, the influence of Sb/Pd ratio on catalytic performance was also checked under optimised reaction conditions. The activity of the catalysts was found to increase continuously with increasing Sb/Pd ratio up to 0.7 and then decreased with further increase in Sb/Pd ratio to 1.75. The catalyst with Sb/Pd ratio of 0.7 exhibited the best performance among all other catalysts of this series giving a conversion of toluene as high as ca. 68% with BA selectivity of 85%. All these catalysts were observed to deactivate with time on stream due to considerable amount of coke deposition. However, these catalysts can be regenerated in air and reused for more number of cycles with consistent performance.     

Selective hydrogenation of furfural to cyclopentanone over Cu-Ni-Al hydrotalcite-based catalysts

A series of Cu-Ni-Al hydrotalcites derived oxides with a (Cu+Ni)/Al mole ratio of 3 with varied Cu/Ni mole ratio (from 0.017 to 0.5, with a Cu ratio of 0.0125 to 0.25) were prepared by co-precipitation method, then applied to the hydrogenation of furfural in aqueous. Their catalytic performance for liquid phase hydrogenation of furfural to prepare cyclopentanone was described in detail, considering reaction temperature, catalyst composition, reaction time and so on. The yield of cyclopentanone was influenced by the mole ratio of Cu-Ni-Al based heterogeneous catalyst and depended on the reaction conditions. The yield of cyclopentanone was up to 95.8% when the reaction was carried out under 413 K with H₂ pressure of 40 bar for 8 h. The catalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and H₂ temperature-programmed reduction (H₂-TPR).     

Thermal behavior of Al/MoO3 xerogel nanocomposites

Sol–gel process using molybdenum alkoxides was employed to prepare Al/MoO₃ xerogel nanocomposites as a thermite with better performance by improvement of interfacial contact area between the oxidizer and fuel. Micromorphology and thermite reaction characteristics of Al/MoO₃ xerogel nanocomposites were analyzed by scanning electron microscopy (SEM) and thermogravimetry/differential scanning calorimetry (TG/DSC), respectively. In the present Al/MoO₃ xerogel system, it was found that exothermic enthalpy increases as the Al/Mo mole ratio increases and then decreases when Al/Mo mole ratio is larger than 6 indicating that optimum mole ratio of Al/Mo is 6 with reaction enthalpy of 420.58 J/g.     

杂多酸催化棓酸正丁酯酯化反应研究

研究了以磷钼酸和磷钨酸为催化剂,由棓酸和正丁醇制备棓酸正丁酯的反应。考察了不同的催化剂用量、醇用量、反应时间对棓酸正丁酯产率的影响。确定了最佳反应条件,棓酸与催化剂磷钼酸的摩尔比为1∶0.0322,丁醇90 mL,反应时间2.5 h;棓酸与催化剂磷钨酸的摩尔比为1∶0.02084,丁醇80 mL,反应时间2.5 h,平均酯化率分别为84.3%和80.2%。在棓酸正丁酯的合成中,采用磷钨酸作催化剂时优于磷钼酸。