聚乙二醇200相转移催化合成6-甲基尿嘧啶

以乙酰乙酸乙酯和尿素为原料,用对甲苯磺酸作催化剂合成6-甲基尿嘧啶,探讨了不同相转移催化剂、带水剂、相转移催化剂用量及脱水缩合时间等因素对反应产物产率的影响。得出最佳工艺条件为:19.8m L乙酰乙酸乙酯、10g尿素,对甲苯磺酸1.2g,150m L石油醚作带水剂,0.3g聚乙二醇200作相转移催化剂,回流脱水缩合8h,产率可达78%。     

棒状FeS2/NiS2和FeP/Ni2P材料的合成与催化性能比较

以Fe(NO3)3?9H2O、Ni(NO3)2?6H2O、硫粉或NaH2PO2?H2O为原料,通过两步法合成了FeS2/NiS2、FeP/Ni2P复合材料,通过XRD、SEM和TEM对材料的结构和形貌进行了表征,研究了其析氧催化性能。结果表明,上述催化剂均具有很好的催化性能。在电流密度为10 mA/cm2时,FeP/Ni2P需要较小的过电位（300 mV）,表现出比FeS2/NiS2（300 mV）更好的催化活性。FeP/Ni2P催化剂相应的塔菲尔斜率值（48 mV/dec）也比FeS2/NiS2 (71 mV/dec)的小,表示在析氧反应中FeP/Ni2P催化剂具有更好的催化动力学性能。     

聚乙二醇200双油酸酯的合成及涤纶工业丝油剂中的应用

研究了聚乙二醇200双油酸酯(PEG200DO)的制备,以聚乙二醇200(PEG200)、油酸为原料,分别以固体酸催化剂(EC-205、HND-26)、对甲苯磺酸、氧化亚锡、氢氧化钾为催化剂,直接酯化法合成PEG200DO.研究反应方式、催化剂类型及用量、反应温度、酸醇投料比等因素对合成的影响,确定最佳的反应条件:油酸...     

聚乙二醇200氯硝柳胺抗血吸虫尾蚴活性及其诱导敏感性研究

为研究标题聚合物对血吸虫尾蚴的作用,测试了该聚合物杀灭尾蚴的活性,同时详细考察了尾蚴对药物的敏感性。实验结果表明,尾蚴直接浸泡在药液中,药物对尾蚴的半数致死浓度LC50为0.338 9μg/cm2;水面药物浓度低于0.178μg/cm2,血吸虫尾蚴对该药物敏感;水面药物浓度为0.25~0.7μg/cm2,浸泡1~2 h后尾蚴对药物的敏感性下降,显示耐药趋势,提示该药物在实际使用过程需要考虑尾蚴对药物的耐药性问题。     

聚乙二醇(200)双甲基丙烯酸酯的合成

以PEG-200和甲基丙烯酸为主要原料,同时加入阻聚添加剂FA03,合成PEG-200双甲基丙烯酸酯。通过正交实验考察了原料配比、催化剂用量、阻聚剂用量、反应时间等因素对产率的影响,最佳工艺条件为PEG- 200与甲基丙烯酸摩尔比为1:2．1;催化剂对甲苯磺酸用量为醇酸总质量的2％;阻聚剂FY51用量为甲基丙烯酸质量的0．2％;反应时间为5 h;阻聚添加剂FA03用量为醇酸总质量的0．2％。最终产品酸值小于0．5 mg KOH／ g,w(固体分)>98％(105℃,20 min),产率大于82％。     

聚乙二醇对纳米氧化锌合成的影响

采用均匀沉淀法,以尿素与无水氯化锌为原料,聚乙二醇(PEG)为表面活性剂,探讨聚乙二醇分子量分别是800、2000、4000和8000以及不同用量对纳米氧化锌颗粒合成的影响,并采用沉降法、斯托克斯(St?ckes)定律计算粒径,SEM表征产品粒径形貌。由实验结果知,当PEG分子量为4000,n(PEG):n(CO(NH_2)_2):n(ZnCl_2)=0.037:4:1(摩尔比)时,合成纳米氧化锌颗粒粒径小,平均粒径约为55.78 nm,粒径分布窄;均匀沉淀法所制备的产品锌含量均高于79.3%,接近理论锌含量(80.7%),产品纯度高。     

低色度聚乙二醇(200)双甲基丙烯酸酯的合成

以聚乙二醇(PEG-200)和甲基丙烯酸甲酯(MMA)为原料,采用酯交换法合成聚乙二醇(200)双甲基丙烯酸酯大分子功能单体。考察了溶剂、催化剂、阻聚剂和脱色剂对酯交换反应的影响。结果表明,在酯交换反应中,溶剂环己烷能够降低反应温度,且易于脱出副产物甲醇。当m(环己烷)∶m(总反应液)=2∶5,m(碳酸钾)∶m(醇酯总质量)=8.5∶100,m(氢醌单甲醚)∶m(醇酯总质量)=1.1∶100和m(脱色剂A)∶m(醇酯总质量)=2.1∶100时,产率可达到80.2%,色度为50 APHA。     

聚乙二醇作为溶剂和催化剂载体在有机合成中的应用

聚乙二醇(PEG)作为一种无毒、热稳定性好、可循环利用和便宜易得的绿色溶剂,与传统的挥发性有机溶剂相比具有更好的稳定性。聚乙二醇(PEG)所负载的催化剂有较高的催化活性,且易于实现催化剂的回收利用,已经被普遍应用于有机合成和催化反应中。综述了近十年来聚乙二醇(PEG)作为溶剂参与的化学反应以及在有机合成与化工中负载催化的应用,介绍了这些反应的特点和优势。     

Synthesis of texture-excellent mesoporous alumina using PEG1000 as structure-directing agent

By varying concentration of PEG1000 as a structure-directing agent,mesoporous alumina with excellent textural properties was synthesized.The prepared mesoporous alumina displays high thermal stability,as shown by its textural properties at different calcination temperatures of 600-850 °C.Characterization by SEM and TEM revealed that the added PEG surfactant induced the formation of petal-like alumina.XRD results clarified that all samples were amorphous and their peaks were around the peaks of γ-alumina.N_2 adsorption-desorption analysis showed that the prepared mesoporous alumina,if with PEG1000 in hydrolysis of aluminum isopropoxide,had excellent textural properties with large specific surface area,high pore volume and suitable pore size.The petal-like structure existing in the alumina samples improved their textural parameters,and the role and influential mechanism of PEG1000 were analyzed.     

Sodium borohydride reduction of ketones,aldehydes and imines using PEG400 as catalyst without solvent

Aldehydes, ketones and imines were readily reduced by sodium borohydride, with the participation of a small amount of water, in good to excellent yields using PEG400 as catalyst in the absence of organic solvents. Copyright © 2005 Society of Chemical Industry     

聚乙二醇催化肉桂醛合成方法研究

研究了不同相对分子质量的聚乙二醇和聚乙二醇不同用量对合成肉桂醛反应产率的影响,并且对该过程的催化作用进行了理论探讨,从实验得出用聚乙二醇-600做相转移催化剂时,产率用量为4×10-3mol时产率最高。     

Thermodynamic Analysis of the Solubility of Isoniazid in (PEG 200 + Water) Cosolvent Mixtures from 278.15 K to 318.15 K

The solubility of drugs in cosolvent systems of pharmaceutical interest is of great importance for understanding and optimizing a large number of processes. Here, we report the solubility of isoniazid in nine (PEG 200 + water) cosolvent mixtures at nine temperatures (278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 318.15 K) determined by UV–vis spectrophotometry. From the solubility data, the thermodynamic solution, mixing, and transfer functions were calculated in addition to performing the enthalpy–entropy compensation analysis. The solubility of isoniazid depends on the concentration of PEG 200 (positive cosolvent effect) and temperature (endothermic process) reaching its maximum solubility in pure PEG 200 at 318.15 K and the lowest solubility in pure water at 278.15 K. The solution process is favored by the solution entropy and according to the enthalpy–entropy compensation analysis it is driven by entropy in mixtures rich in water and by enthalpy in mixtures rich in PEG 200.     

CO2/N2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures

The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.     

聚苯乙烯固载聚乙二醇催化合成1,4-二乙氧基苯

应用二乙烯苯交联的聚苯乙烯－聚乙二醇４００（ＤＶＢ－ＰＳ－ＰＥＧ－４００）树脂作相转移催化剂催化合成了１,４－二乙氧基苯,并用红外光谱、元素分析对产物进行了测定。此法具有产率高,易操作,反应条件温和,催化剂能重复使用,效果良好的优点。     

Effect of NiS addition on nitridation of alumina to aluminum nitride using polymeric carbon nitride as a nitridation reagent

We investigated the effect of adding nickel(II) sulfide (NiS) on nitridation of alumina (Al₂O₃) to aluminum nitride (AlN) using polymeric carbon nitride (PCN), which was synthesized by polymerization of dicyandiamide at 500 °C. The product powders obtained from nitridation of a mixture of δ-Al₂O₃ and NiS powders (mole ratio of 1:0.01) at various reaction temperatures were characterized by powder X-ray diffraction, ²⁷Al magic-angle spinning nuclear magnetic resonance, and Raman spectroscopy. δ-Al₂O₃ began to convert to AlN at 900 °C and completely converted to AlN at 1300 °C. The as-synthesized sample powders contained nitrogen-doped carbon microtubes (N-doped CMTs) with a length of several tens of mm and thickness of ca. 3 µm. The addition of NiS to δ-Al₂O₃ resulted in the enhancement of the amount of N-doped CMTs and nitridation rate, which might be due to the catalytic action of Ni particles on the thermal decomposition of vaporized PCN. The change in Raman spectra with reaction temperatures indicated that the crystallinity of N-doped CMTs was increased by calcining at higher reaction temperatures.     

聚乙二醇在有机合成中的应用研究进展

综述了聚乙二醇（PEG）作为一种环境友好型的相转移催化剂、溶剂和有机分子支载体在有机合成中的应用,介绍了PEG的作用原理和其与新技术结合的研究成果,并对其今后的主要发展方向进行了展望。