Mixed micelles of hexadecylpyridinium bromide + tetradecyltrimethylammonium bromide in aqueous glycol oligomers

Conductances of hexadecylpyridinium bromide (HPyBr) + tetradecyltrimethylammonium bromide (TTAB) mixtures over the entire mole fraction range of HPyBr (α_HPyBr) were measured in pure water as well as in the presence of various aqueous ethylene glycol oligomers containing 10 and 30 wt% of each additive in their respective binary mixtures at 30°C. Each conductivity curve shows two breaks corresponding to two critical micelle concentrations (cmc; C₁ and C₂ over the whole mole fraction range of HPyBr + TTAB mixtures except in the presence of pure HPyBr and TTAB, where a single break was observed. From the conductivity data, various micellar paramelers in the absence and presence of glycol additives were computed. A variation in the micellar parameters in the presence of additive showed that additive introduction mainly influence the medium properties and therefore the micellar properties. However, no significant micelle-glycol interactions were observed even with an increase in the number of repeating units from ethylene glycol to polyethylene glycol 600. The mixing behavior of HPyBr + TTAB is close to nonideal and is identical in pure water and in the presence of various glycols. This has been attributed to the presence of synergistic interactions between unlike monomers at C₁ that are not influenced even by the presence of additives. The appearance of the second cmc is mainly attributed to structural transitions of the mixed micelles at C₁ with a further increase in surfactant concentration.     

Solubilities of CO2 in some glycol ethers under high pressure by experimental determination and correlation☆

The binary vapor–liquid equilibrium data of CO_2 in diethylene glycol(monomethyl,monoethyl,monobutyl,dimethyl,diethyl,dibutyl)ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constant-volume method.It was found by contrast that the ether group in solvents can promote the CO_2 absorption,but the hydroxyl group will inhibit the CO_2 absorption.Furthermore,the solubilities of CO_2 showed an upward trend with the increasing molecular lengths of absorbents.The experimental data were also correlated with a modified Patel–Teja equation of state(PT EOS)combined with the traditional van der Waals one-fluid mixing rules and the results showed a satisfactory agreement between the model and the experimental data.     

油漆涂层中乙二醇单甲醚和乙二醇单乙醚残留量的检测

采用超声波萃取方法和气相色谱质谱联用技术(GC-MS),对油漆涂层中的乙二醇单甲醚和乙二醇单乙醚残留量进行定性定量检测技术研究,得到乙二醇单甲醚的仪器定性检出限为0.075 mg/L,方法的定量检出限最低为25 mg/kg;乙二醇单乙醚的仪器定性检出限为0.033 mg/L,方法的定量检出限最低为11 mg/kg。两者的标准工作溶液(2~50 mg/L)线性相关系数r均为0.999以上,连续进行6次测试各浓度响应峰面积的RSD在10%以内。进行前处理的正交实验,最佳萃取条件是使用甲醇在1130 W超声波萃取30分钟。     

Alkaline depolymerization of poly(trimethylene terephthalate)

The purpose of this study was to investigate the effects of reaction media, composition, and temperature on the rate of the alkaline depolymerization of poly(trimethylene terephthalate) (PTT). The alkaline depolymerization of PTT was carried out at 160–190°C in ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), ethylene glycol monobutyl ether (EGMBE), diethylene glycol monoethyl ether (DEGMEE), and a mixture of these solvents. During the reaction, PTT was quantitatively converted to disodium terephthalate and 1,3-propanediol. The alkaline depolymerization reaction rate constants were calculated based on the concentration of sodium carboxylate, which was equivalent to the molar amount of sodium hydroxide. The depolymerization rate of PTT was increased by increasing the reaction temperature and by adding ethereal solvents. Moreover, the depolymerization rate was significantly accelerated in the order of EG < DEG < TEG < EGMBE < DEGMEE. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 99–107, 2001     

Polymer-Induced incompatibility in the mixed micelle formation of cationic surfactants with bulky polar head groups

The conductances of tetradecyltrimethylammonium bromide (TTAB)+tetradecyl triphenylphosphonium bromide (TTPB) mixtures over the entire mole fraction range were measured in aqueous poly(vinyl pyrrolidone) (PVP) containing 1 to 10 wt% of PVP at 30°C. Each conductivity (κ) curve showed a single break corresponding to the mixed micelle formation in the presence of PVP over the whole mole fraction range. From the conductivity data, various micellar parameters in the presence of PVP were computed and discussed in terms of micelle-polymer interactions. The mixing behavior of TTAB+TTPB in pure water was close to ideal, whereas in the presence of PVP a significant degree of nonideality was sobserved that was evaluated by computing the mole fraction of TTAB in the mixed micelle state (x ₁) and the interanction parameter (β) by using the regular solution approach. The former is less than the value in the ideal state, and the latter is much greater, indicating the enhancement in the antagonistic mixing behavior of TTAB+TTPB in the presence of PVP. The results have been explained on the basis of an increase in the incompatibility between the monomers of TTAB and TTPB in the mixed state due to the steric hindrances created by the PVP upon adsorption at the micelle-solution interface. The results have also been further supported by comparing with those of structurally similar cationic binary combinations in the presence of PVP.     

Surfactant-polymer interactions: Mixed micelles of hexadecylpyridinium bromide and trimethyltetradecylammonium bromide in aqueous poly(vinylpyrrolidone) solution

The conductance of hexadecylpyridinium bromide (HPyBr) and trimethyltetradecylammonium bromide (TTAB) mixtures over the entire mole fraction range of HPyBr (α_HPyBr) was measured in aqueous poly(vinylpyrrolidone) (PVP) solution containing 1, 5, and 10 wt% PVP at 30°C. Each conductivity curve showed two breaks corresponding to two aggregations throughout the whole mole fraction range of HPyBr and TTAB mixtures except for pure TTAB for which a single break corresponding to the conventional critical micelle concentration was observed. The two aggregation processes in the presence of low amounts of PVP were mostly similar to those in pure water, however, 10 wt% PVP shifted the break, corresponding to the second aggregation, toward the higher value. This was attributed to HPyBr/PVP interactions, which were also evident from the appearance of a second break in the conductivity (κ) plot of pure HPyBr in aqueous 10 wt% PVP. From conductivity data, various micellar parameters in the presence of PVP were determined and discussed from the standpoint of micelle-polymer interactions. The mixing behavior of HPyBr and TTAB corresponding to the first break in the presence of PVP was ideal for the most part and identical to that in pure water.     

农药液体制剂中5种助剂的气相色谱测定方法

本文建立了农药液体制剂中乙二醇甲醚、乙二醇乙醚、乙二醇甲醚醋酸酯、乙二醇乙醚醋酸酯、环己酮5种有害助剂的气相色谱法定量分析的方法。采用甲醇为溶剂,使用HP-INNOWAX毛细管柱,进样口和检测器温度为220℃,柱温采用程序升温进行测定。方法的线性决定系数大于0.9950,添加回收率在96.1%~102.2%之间,定量限(LOQ)为1.4~3.8 mg·L-1。采用所建立方法对市售的7种不同剂型的农药产品中5种有害助剂的含量进行了分析,环己酮成分在部分制剂中被检出。     

常压下二乙二醇单乙醚和水二元体系不同温度下的密度、黏度及过量性质

Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylene glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressure, with a capillary pycnometer and Ubbelohde capillary viscometer respectively. From the experimental data, the excess molar volume VE, viscosity deviation &#61508;η, and the excess energy of activation for viscous flow &#61508;G*E were calculated. These data were correlated by the Redlich-Kister type equa-tions to obtain the coefficients and standard deviations. The results showed a strong molecular interaction between diethylene glycol monoethyl ether and water.     

工作场所空气中三种烷氧基乙醇化合物的同时测定法

建立了工作场所空气中2-甲氧基乙醇(EM)、2-乙氧基乙醇(EE)、2-丁氧基乙醇(EB)的溶剂解吸气相色谱同时测定法。采用活性炭管采集,溶剂解吸,毛细管色谱柱分离的气相色谱(FID)测定方法。EM、EE、EB在本方法规定的浓度范围内线性关系良好,相关系数均大于0.999,检出限均为0.50 mg/L,最低检出浓度均为0.67 mg/m3(以采集3.0 L空气计)。相对标准偏差(RSD)为0.4%～1.8%(n=6),平均解吸效率为97.3%～101.1%,样品在室温下至少可保存7天。该方法灵敏度高,精密度好,操作简单,适用于工作场所空气中EM、EE、EB的同时测定。     

分子筛负载TiO2／SO4^2—催化合成乙二醇单乙醚乙酯

采用液相沉积法制备了由分子筛负载TiO2/SO4^2-的固体超强酸催化剂，考察了该催化剂对乙二醇单乙醚与乙酸酯化的反应条件：反应物醇酸摩尔比1：1.3，催化剂用量5％（以乙二醇单乙醚质量为基准），催化剂活化温度550℃，并以此条件合成了乙二醇单惭醚乙酯，产率为84.6％。     

Organic Additives and Electrolytes as Cloud Point Modifiers in Octylphenol Ethoxylate Solutions

Cloud point measurements of nonionic surfactant Triton X-100, an octylphenol ethoxylate, were carried out in the absence and presence of various organic additives such as n-alkanols (methanol, ethanol, propanol and butanol), glycols (ethylene glycol, diethylene glycol and triethylene glycol), glycol ethers (ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and ethylene glycol monobutyl ether (EGMBE)) and electrolytes (LiCl, KCl, NaF, NaCl, NaBr, NaI, MgCl₂ and AlCl₃). The combined effect of these organic additives and electrolytes on cloud point (CP) measurement was also investigated. The effect of nature of cation, anion and valency of cation on CP is also reported. Among the n-alkanols and glycol ethers as additives, n-butanol and EGMBE were found to decrease the CP while all other additives increase the cloud point. The addition of electrolytes (LiCl, NaCl and KCl) to the solution of Triton X-100 (TX-100) decreases the CP but the rate of decrease in CP with concentration does not follow the lyotropic series of effect. Sodium halides (except NaI) also decrease the CP and the rate of decrease follows the lyotropic series of effect even in the presence of organic additives. NaI is a water structure breaker, hence it increases the cloud point. Further, cations of increasing valency lessen the depression in CP of TX-100 with the rate of decrease in CP following the order Na⁺ > Mg²⁺ > Al³⁺ even in the presence of organic additives.

抗氧剂二亚磷酸双酚A四二甘醇（及其单丁醚）酯的合成

叙述以亚磷酸三苯酯,双酚A及二甘醇及其二甘醇单丁醚为原料,采用酯交换反应方法,合成二亚磷酸双酚A四二甘醇(及二甘醇单丁醚)酯,讨论了原料配比,催化剂及用量,反应温度及反应时间对转化率的影响。     

低温固化阴极电泳涂料的制备及研究

以乙二醇单丁醚和乙二醇单乙醚为封闭剂,全封闭的甲苯二异氰酸酯为交联剂制得了一种阳离子型环氧树脂,同时对环氧树脂阴极电泳涂料性能进行了研究,并系统的探讨了电泳涂料的配方和工艺对涂膜的影响。结果表明,最佳封闭温度为50℃,接枝温度为80℃时1,50℃烘烤30 min得到外观平整光滑、附着力强、耐水性强的无色透明漆膜。     

分子筛负载TiO_2/SO_4~(2-)催化合成乙二醇单乙醚乙酯

采用液相沉积法制备了由分子筛负载TiO2 /SO2 -4 的固体超强酸催化剂 ,考察了该催化剂对乙二醇单乙醚与乙酸酯化的反应条件 :反应物醇酸摩尔比 1∶1 3,催化剂用量 5 % (以乙二醇单乙醚质量为基准 ) ,催化剂活化温度 5 5 0℃ ,并以此条件合成了乙二醇单乙醚乙酯 ,产率为 84 6 %。     

CO《,2》在碳酸二甲酯混合溶剂中的溶解度

为改善碳酸二甲酯(DMC),对CO<,2>气体的吸收性能,降低溶剂成本,在DMC中添加一定量的氨水、助溶剂形成拟均相混合CO<,2>吸收剂.用恒定容积法考察了不同条件下(助溶剂的类型、二乙二醇乙醚的比例、氨水的质量分数、氨水的比例和温度)混合溶剂(DMC+质量分数10%氨水+二乙二醇乙醚)的CO<,2>吸收性能.结果表...     

四水硫酸铈催化合成乙二醇单乙醚乙酸酯

以乙二醇单乙醚和乙酸为主要原料,以四水硫酸铈为催化剂,环己烷为带水剂,合成了乙二醇单乙醚乙酸酯。采用IR、1HNMR等对其结构进行了确证,考察了乙二醇单乙醚和乙酸的摩尔比、催化剂种类和用量、带水剂用量、反应温度、反应时间等因素对反应的影响,得到了适宜的反应条件为:以0.2 mol乙二醇单乙醚为基准,n(乙酸)∶n(乙二醇单乙醚)=1.5∶1,m(四水硫酸铈)∶m(乙二醇单乙醚)=0.05∶1,环己烷9 mL,反应温度130℃,反应时间2.5 h。在该条件下,乙二醇单乙醚乙酸酯收率达97%以上。     

A1C13／（NH4）2HPO4催化直接法合成乙二醇单甲醚

开发了非石油路线法合成乙二醇单甲醚的新工艺,即以煤制乙二醇为原料和甲醇直接法合成乙二醇单甲醚。以A1Cl3／（NH4）2HPO4做复合催化剂,考察了A1C13／（NH4）2HPO2复合催化剂不同比例、催化剂的用量、反应温度、压力、时间等因素对反应的影响。确定适宜条件为AICl3／（NH4）2HPO4复合催化剂的质量比为1：2．5,催化剂的质量占乙二醇质量的4％,乙二醇／甲醇物质的量比为1：4,反应温度260℃,反应时间4h,反应压力7MPa,此时乙二醇转化率为39％,乙二醇单甲醚选择性84％,乙二醇单甲醚收率32％。并对反应机理进行了初步探讨。     

丙烯醛温和液相反应制备3-甲基吡啶工艺

以丙烯醛为原料,通过单因素实验,建立了优化的温和液相反应合成3-甲基吡啶的优化工艺条件：以乙二醇单丁醚为溶剂,反应温度140℃,料液比n(丙烯醛):n(乙二醇单丁醚)=1:33,n(丙烯醛):n(乙酸铵)=1:8,w(丙烯醛正丁酸溶液)=8%,m(丙烯醛):m(SO24-/TiO2-HZSM-5催化剂)=1:1.4。在优化条件下,实现了丙烯醛转化率100%,3-甲基吡啶选择性49.92%。     

Determination of Surface Areas of Active Carbons by Retention of Ethylene Glycol and Ethylene Glycol Monoethyl Ether

Abstract

Experiments of ethylene glycol and ethylene glycol monoethyl ether retention on some active carbons were carried out to measure the surface areas of the carbons. Some differences were observed between nitrogen-specific surface area values and those obtained from ethylene glycol retention. However, since the differences decreased through an increase of surface oxygen content as a result of treatment of the carbons with H₂O₂, it was evident that ethylene glycol retention depended upon the surface oxygen content. Also, the surface area values obtained from retention of ethylene glycol monoethyl ether did not depend upon the surface oxygen content. Measurements of the ethylene glycol monoethyl ether retention process could be performed in a shorter time than the equivalent ethylene glycol retention measurements.     

液晶显示器清洗剂配方开发

在以脂肪醇聚氧乙烯甲基醚、脂肪醇聚氧乙烯聚丙烯醚、脂肪醇聚氧乙烯醚、乙醇胺、乙二醇丁醚、乙二胺四乙酸为主要原料制备的清洗剂配方中,研究了脂肪醇聚氧乙烯醚、乙醇胺、乙二醇丁醚的用量对清洗剂清洗效果的影响。通过正交试验优化了实验参数,得到了所选水平下的最佳配方:脂肪醇聚氧乙烯醚用量为5%,乙醇胺用量为5%,乙二醇丁醚用量为15%。该配方下清洗剂的泡沫较少,碱性较强,清洗效果最佳。