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硫酸镍催化合成紫罗兰酮 总被引:5,自引:0,他引:5
用硫酸镍催化假性紫罗兰酮的环化反应,得到了较高产率的紫罗兰酮。探索了催化剂用量、反应温度、反应时间、溶剂用量和溶剂的种类等因素对该环化反应的影响。最佳合成条件如下:5.6mL(79.6%)假性紫罗兰酮,催化剂用量为假性紫罗兰酮的3%(摩尔百分率),甲苯(溶剂)用量为8mL,环化反应温度为40~50℃,反应时间为2.5h,在此合成条件下所得紫罗兰酮的产率为67.4%。选择极性较大的物质(如三氯甲烷)作溶剂有利于该环化反应的进行。 相似文献
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采用沉淀.浸渍法制备了复合不同Ce摩尔含量的稀土固体超强酸Sz0827ZrO2-CeO2,研究了其在花生壳水解制备乙酰丙酸反应中的催化效果,考察了水解温度、水解时间、固体酸用量和液固比(mL/g)对乙酰丙酸产率的影响。实验发现,ce含量为4%的固体酸催化性能最佳,最佳工艺条件为:水解温度243℃,水解时间35min,固体酸用量5.2%。在此条件下,乙酰丙酸产率为35.86%。 相似文献
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以氯乙酸钠、硫代硫酸钠为原料,固体超强酸做催化剂,合成了Bunte盐.Bunte盐经酸解、还原、萃取后减压精馏得到巯基乙酸;巯基乙酸异辛酯的合成采用萃取酯化法,以异辛醇作萃取剂从稀巯基乙酸水溶液中萃取出巯基乙酸后,加入催化剂,在蒸出异辛醇的同时发生酯化反应,经减压蒸馏得到巯基乙酸异辛醇产品.考察了各因素对产品产率的影响,得出最佳工艺:合成巯基乙酸时反应时间为90 min,硫酸用量占反应物的质量分数为10%,锌粉用量占反应物的质量分数为2.0%;酯化过程中异辛醇与巯基乙酸摩尔比为2.2∶1.0,催化剂用量占反应物的质量分数为0.6%,反应温度为120~130℃,此工艺条件下酯化率大于99%,产率大于99%. 相似文献
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甲基丙烯酸缩水甘油酯的合成 总被引:3,自引:0,他引:3
在季铵盐催化剂和对苯二酚阻剂聚剂存在下,由甲基丙烯酸甲酯(MMA)和环氧氯丙烷合成了甲基丙烯酸缩水甘油酯(GMA)。通过正交实验设计,得到了最佳反应条件;反应温度100 ̄105℃,反应时间4h,四丁基溴化铵(TBAB)催化剂的用量为1.2g。GMA的产率为83.6%,纯度为98%。 相似文献
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酯交换法合成甲基丙烯酸二甲胺基乙酯 总被引:1,自引:0,他引:1
以甲基丙烯酸甲酯、二甲氨基乙醇为原料,有机锡化合物为催化剂,吩噻嗪为阻聚剂,采用酯交换法合成了甲基丙烯酸二甲胺基乙酯。确定了合成的最佳工艺,即甲基丙烯酸甲酯与二甲氨基乙醇的量比为2.2:1.0,催化剂用量为反应液总质量的1.2%,阻聚剂用量为反应液总质量的0.2%,反应温度为体系回流温度,在此条件下,产率达96%以上。 相似文献
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采用金属负载型阳离子交换树脂作催化剂,乙醇和丁二酸酐为原料,对琥珀酸单乙酯的合成进行了研究,确定了最佳工艺条件:原料摩尔比n(乙醇),n(丁二酸酐)=1.3:1,催化剂用量占丁二酸酐用量的15%。反应温度85℃,反应时间90min,乙酸正丁酯的产率达到93%以上。 相似文献
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采用种子乳液聚合法合成新型低温反应型聚丙烯酸酯乳液粘合剂,即以丙烯酸丁酯(BA)、丙烯酸异辛酯(EHA)、苯乙烯(St)为软、硬单体,丙烯酸(AA)为功能单体,以过硫酸钾为引发剂,并选用一种适当的交联单体合成了性能优良的聚丙烯酸酯涂料印花粘合剂。讨论了引发剂用量、乳化剂用量、阴/非离子乳化剂的配比、乳液滴加时间、保温时间等对聚合物的影响。确定了乳液聚合最佳工艺条件:乳化剂用量为o8%,阴/非乳化剂质量比为4:3,引发剂用量为0.8%,乳液滴加时间60min,保温时间60min。 相似文献
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A multiphase second-order moment turbulent model was developed including an improved closure Reynolds stress transport to describe effectively the anisotropic characteristics of bubble-liquid turbulent flow. The two-phase hydrodynamics in a bubble column were numerically simulated by an in-house code. The effect of the amount of jetting holes on bubble-liquid hydrodynamics in relationship with a cell culture was investigated. Firstly, the bubble energy production correlation was proposed to verify the higher cell damage rate near gas inlet regions. The larger amounts of jetting holes resulted in an increase of bubble stress, bubble kinetic energy, and energy dissipation, particularly bubble energy production at the near gas inlet, which boosted cell damage. 相似文献
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以醋酸纤维素(CA)为原料,采用溶液浇铸法成膜。用物理包埋法将荧光指示剂固定CA膜中。以戊二醛为交联剂,将葡萄糖氧化酶固定于膜表面。研究了高碘酸钠、乙二胺、戊二醛、给酶量、pH值等固定化条件对酶活的影响,确定了优化的固定条件:在室温下与0.5 mol/L的高碘酸钠反应30 min;与0.04 mol/L的乙二胺反应150 min时;与溶度为1.5%(v/v)的戊二醛交联120 min;在4℃条件下,在pH6.5、给酶量35 mg/mL的酶液中交联21 h。利用SEM分析表明,荧光指示剂均匀分布膜中,成膜质量较好。通过优化固定条件,把荧光指示剂和葡萄糖氧化物酶(GOD)同时固定醋酸纤维素膜上,可以得到同时具有光敏感性和酶催化能力的复合敏感膜。 相似文献
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The Large-eddy simulation (LES) with two-way coupling is used to study bubble-liquid two-phase confined multiple jets discharged into a 2D channel.The LES results reveal the large-eddy vortex structures of both liquid flow and bubble motion,the shear-generated and bubble-induced liquid turbulence,and indicate much stronger bubble fluctuation than that of the liquid,the enhancement of liquid turbulence by bubbles.Both shear and bubble-liquid interaction are important for the liquid turbulence generation in the case studied. 相似文献
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Two versions of the second-order moment two-phase turbulence model are proposed in this study for simulating bubble-liquid two-phase turbulent velocity fluctuations and their interactions in bubble-liquid flows under the dispersed bubble regime. One of them is a full transport equation model; the other is an algebraic stresses model. The proposed model is used to simulate liquid and gas mean velocities, gas volume fraction, liquid and gas Reynolds stresses and turbulent kinetic energy in a 2-D bubble column. Furthermore, the bubble and liquid velocities, Reynolds stresses and gas volume fraction are measured using the PIV. The simulation results are in good agreement with the PIV results and experimental data in the literature. The studies reveal the liquid recirculation and bubble up-rising flow patterns, and anisotropic liquid and bubble normal Reynolds stresses. Bubble fluctuation is observed to be stronger than liquid fluctuation. Moreover, both the liquid velocity gradient and bubble-liquid interaction are important for the generation of liquid turbulence. 相似文献
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低温法制备二氧化钛薄膜及其光催化氧化处理电镀含铬废水 总被引:1,自引:0,他引:1
以钛酸四丁酯为原料,采用微波辅助低温法在玻璃表面制备锐钛矿结构的二氧化钛薄膜。分别用X射线衍射法(XRD)和扫描电子显微镜(SEM)表征其相结构和表面形貌;通过光催化降解实际电镀含铬废水实验,探讨了光源、废水pH、废水初始浓度、光照时间及涂膜层数对总铬去除率的影响。光催化氧化的最优条件为:废水初始浓度3 000~9 000 mg/L,pH=8.3,负载4层薄膜,254 nm紫外光照射3 h。在最优条件下,废水的总铬去除率高达99.8%。 相似文献
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引 言钇稳定二氧化锆 (YSZ)是制备氧化物燃料电池和氧传感器的重要材料 .电解质薄膜化是开发高输出电流密度的固体氧化物燃料电池和高灵敏度的传感器的研究方向 .电化学气相沉积 (EVD) [1~ 3] 制得的薄膜致密 ,且厚度仅 2 0~ 4 0 μm ,薄膜性能优良 ,但设备复杂 ,制备成本高 ,反应生成的氯气腐蚀性大 .激光沉积法具有设备复杂、成本高等问题 .等离子喷涂 (VPS、APS) [4 ,5] 适于大规模制膜 ,但薄膜不够致密 ,裂缝较多 .溶胶 -凝胶法 (Sol -Gel) [4 ,6 ,7] 制得的YSZ薄膜致密且薄 ,设备简单 ,但对于基片要求很严 ,… 相似文献
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Sezen Kurşun Bilge Zabcı Ekinci Ergun Ekinci 《Polymer-Plastics Technology and Engineering》2013,52(12):1209-1212
Electropolymerized polytyramine film was proposed for determination of uric acid in the presence of ascorbic acid. The influence of electropolymerization conditions on performance of the polytyramine film was examined to obtain the optimal experimental parameters. The voltammetric results demonstrated that polytyramine film obtained at the optimized conditions allowed penetration of large amounts of uric acid while blocking the permeation of electroactive (ascorbic acid, cysteine and oxalic acid) and non-electroactive interferents (lactose, sucrose and urea) through film in PBS. Therefore, it has been claimed that the polymeric film could be used as uric acid-selective membrane over a broad range of interference. 相似文献
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