乙酸乙酯-异丙醇二元系的黏度行为和表面性质

常压下测定了乙酸乙酯和异丙醇二元系在298.15～323.15 K下的黏度和表面张力,计算了黏度偏差、过量流动活化自由能和表面张力偏差,采用Redlich-Kister方程进行了关联。结果表明,黏度偏差、过量流动活化自由能和表面张力偏差均为负值,且显示了相同的变化趋势,随温度降低而偏差增大。利用表面张力数据进一步考察了混合液表面熵和表面焓,并基于扩展的Langmuir模型,计算了异丙醇的疏液性β及其表面组成。β值表明异丙醇对表面有更大的亲和力,其表面组成始终高于在溶液本体中的组成。     

1,2-丙二醇制备工艺研究进展

综述了丙二醇生产工艺的研究进展,并对相关生产方法进行了比较,提出甘油氢解制备丙二醇发展潜力大,甘油加氢制备1,2-丙二醇(1,2-PDO)的技术比较成熟,但还需要对催化剂进一步的研究。     

锌盐催化尿素和1,2-丙二醇合成碳酸丙烯酯

考察了各种锌盐催化尿素和1,2-丙二醇(PG)合成碳酸丙烯酯(PC)的催化性能。几种催化剂中,氯化锌具有最佳的催化性能。以氯化锌为模板催化剂,考察了反应条件如:反应温度、反应时间和催化剂用量对催化效果的影响。结果表明,在尿素3.0 g、PG 7.62 g、反应温度170℃、反应时间3 h、催化剂用量0.4 g时,PC收率可达到82.9%。傅里叶红外表征进一步说明,催化剂的催化活性与它们活化尿素分解为异氰酸的能力有关;然后,异氰酸与催化剂作用生成中间物种,在PG的作用下最终生成PC。最后,基于以上催化测试和表征结果,提出了尿素和PG反应合成PC可能的催化反应机理。     

3-甲胺基-1,2-丙二醇生产新工艺

环氧氯丙烷在复合酸性双组分催化剂作用下经过水解、蒸馏等过程制得纯度99.5%(G/G)以上的中间体3-氯-1,2-丙二醇(氯代甘油),然后与一甲胺在碱性催化剂存在下进行胺化反应,反应液经过脱除去一甲胺,除去水,过滤除盐,真空刮板薄膜蒸发等过程得到含量99.5%(气相色谱分析)、无色透明的3-甲胺基-1,2-丙二醇。该工艺已在100t/a装置上运行近一年。     

香料环己酮-1,2-丙二醇缩酮的合成

以环己酮和１,２－丙二醇为原料,在Ｆｅ３＋－ＵＲ的催化作用下合成了香料环己酮－１,２－丙二醇缩酮,在最佳反应条件下,产物收率为９２．６％。     

离子液体[BPy]BF4和甲醇二元混合体系的超额摩尔体积、折射率和黏度

合成了室温离子液体N-丁基吡啶四氟硼酸盐([BPy]BF4),通过核磁共振1H-NMR和红外光谱IR对其结构进行了表征.在298.15 K和常压下,采用U形振荡管密度计测定[BPy]BF4-甲醇体系的密度;用阿贝尔折射仪测定了该二元混合体系在相同温度和压力下的折射率;用乌氏黏度计测定了该二元混合体系在相同温度和压力下的...     

BuNENA/DMSO二元体系密度、黏度测定及关联

利用密度瓶和乌氏黏度计分别测定了25,40,50,70℃时BuNENA/DMSO二元体系的密度、黏度,并对黏度与温度、组成的关系进行了多项式回归,模型计算值平均相对误差在0.17%—1.53%。由密度数据计算出超额摩尔体积VmE,由黏度数据计算出不同温度、组成下的超额黏度Δη,其中VEm为正值,Δη为负值。对混合液在不同温度下的VmE与组成的关系用Redlich-Kister方程进行了关联,平均相对误差小于3%。     

酯交换法1,2-丙二醇的提纯新工艺

研究了一种提纯酯交换法1,2-丙二醇的新工艺。针对现有碳酸二甲酯装置联产的1,2-丙二醇存在产品容易变色、刺激性气味较大而不能达到医药级的问题,分析了酯交换法联产1,2-丙二醇质量差的原因,并提出了一种提纯酯交换法1,2-丙二醇的新工艺。经过提纯后的1,2-丙二醇达到了医药级要求(USP、EP标准),能够广泛应用于医药、食品、香精、香料、化妆品等行业。     

1,2-丙二醇在聚酯合成中的应用研究

以1,2-丙二醇作为改性共聚酯合成过程中的二元醇组分,采用对苯二甲酸(PTA)、乙二醇(EG)和1,2-丙二醇为基本原料,通过熔融缩聚的工艺路线,得到改性共聚酯新材料,对1,2-丙二醇在聚酯合成中的应用进行研究。     

工业级1,2-丙二醇去异味精制研究

酯交换法生产的高纯度的工业级1,2-丙二醇产品具有刺激性气味。首先采用气相色谱-质谱联用分析杂质组成,判定产品引起异味的组分。其次,基于产品组分性质差异,用间歇精馏手段,在73 k Pa,回流比3,塔釜加热功率为120 W条件下实验,去除产生异味的组分,得到无气味的1,2-丙二醇医药级产品。从实验结果可以看出,造成产品异味的是甲醇、碳酸二甲酯及丙二醇甲醚。通过间歇精馏实验,可以去除引起异味的杂质,得到纯度> 99.5%的产品,有效的增加产品价值,提高企业经济效益。     

乙酸乙酯-异丙醇混合液的密度和折光率

常压下测定了乙酸乙酯-异丙醇二元混合液在293.15—318.15 K下的密度和折光率,建立了该二元混合液密度与组成和温度关系的计算方程。计算了过量摩尔体积、折光率偏差,分别用Redlich-Kister方程进行了关联。过量摩尔体积在全摩尔分数范围内为正值,而折光率偏差为负值,且均随温度升高而偏差增大。利用Lorentz-Lorenz关系式计算了二元体系的摩尔折光率和摩尔折光率偏差,偏差亦随温度升高而增大。     

乙酸乙酯/四氯化碳二元混合体系的体积性质

常压下测定了乙酸乙酯与四氯化碳二元体系在288.15-323.15 K内全摩尔分数范围的密度,分别建立了该二元体系密度与组成和温度的计算方程.在此基础上,计算了该二元体系的超额摩尔体积,结果表明:该二元体系的超额摩尔体积在所测定温度和全摩尔分数范围内均呈正偏差,且均随温度的升高而偏差增大,并利用Redlich-Kist...     

Catalytic conversion of ethyl lactate to 1,2-propanediol over CuO

An efficient conversion of biomass-derived ethyl lactate to 1,2-propanediol (1,2-PDO) over CuO was investigated. Among the catalysts we tested, CuO, Cu₂O and Co showed excellent catalytic activity for the conversion of ethyl lactate to 1,2-PDO in water, and CuO was more active and gave the best result. The 1,2-PDO yield of 93.6% was achieved when Zn acted as a reductant. The results indicated that in situ formed hydrogen by the oxidation of Zn in water is more effective than gaseous hydrogen, which failed to produce the 1,2-PDO from ethyl lactate. From a practical point of view, the present method may provide a useful route for the production of 1,2-PDO from ethyl lactate.     

Viscosity behaviour of poly(ethyl methacrylate) in the ethyl acetate/tert-butanol binary mixture: total and preferential adsorption

The behaviour of poly(ethyl methacrylate) (PEMA) in the ethyl acetate (1)/tert-butanol (2) binary mixture is studied by laser light scattering, differential refractometry and viscometry. Ethyl acetate is a solvent for the polymer and tert-butanol is a precipitant. Preferential adsorption of tert-butanol up to 15% alcohol in the binary mixture is observed, ethyl acetate being preferentially adsorbed in the macromolecular coil at higher percentage of alcohol in the solvent mixture. Total adsorption of PEMA is independent of the amount of tert-butanol in the solvent. Various theoretical expressions for the preferential and total adsorption coefficients are used; their agreement or disagreement with the experimental results is explained on the basis of polymer-solvent interactions.     

Cu-ZnO催化剂用于乳酸乙酯气相加氢制1,2-丙二醇的研究

在固定床反应器上考察了通过共沉淀法制备得到的一系列不同铜锌比的Cu-ZnO催化剂用于乳酸乙酯制1,2-丙二醇的催化效果。研究发现在铜锌比为2∶1时,催化剂具有较高的活性。在反应温度为220℃和反应压力为4.0 MPa的条件下,乳酸乙酯转化率达99.2%,1,2-丙二醇选择性达92.5%。对催化剂进行了BET、XRD、TPR等表征,初步研究了催化剂的结构与性能之间的关系。     

Mixing properties of isopropyl acetate+aromatic hydrocarbons at 298.15 K: Density,refractive index and isentropic compressibility

We present new experimental data of density, refractive index and speed of sound for the binaries of isopropyl acetate+(toluene, ethylbenzene, p-xylene, mesitylene, isopropylbenzene, butylbenzene, isobutylbenzene, or t-butylbenzene) at T=298.15 K. and standard conditions, and the corresponding computed derived magnitudes (change of isentropic compressibility, change of refractive index on mixing, and excess molar volume). The mixtures show a clear expansive tendency for the highest molar weight compounds and the steric hindrance role of the aromatic chemicals being analyzed to the light of the non-ideality on mixing. A good agreement among experimental data and the values estimated by theoretical procedures was obtained.     

萃取法分离乙腈、乙酸乙酯和水混合物的研究

为了从制药废料中回收乙腈和乙酸乙酯,研究了反萃取精馏分离法在分离乙腈-乙酸乙酯中的应用,确定了首先进行预处理,然后进行萃取精馏的工艺过程及工艺条件。采用以上技术从废液中回收乙酸乙酯,乙酸乙酯含量达到98.5%以上。     

Density and viscosity of the binary polyethylene glycol/CO2 systems

Density of CO₂ saturated solutions of polyethylene glycols (PEGs) of different molecular weight was measured in pressure range from 8.0 MPa up to 47.7 MPa at a temperature of 343 K by a volumetric method. To validate the method density of pure CO₂ was measured at different pressures and a temperature of 293 K. The results were compared to the literature data and the accuracy was better than 2%. The density was between 1.17 g/mL for PEG 1000/CO₂ at 14.5 MPa and 1.78 g/mL for the system PEG 4000/CO₂ at 35 MPa. Further, the data were compared to results, obtained by a gravimetric method using magnetic suspension balance (MSB).Viscosity of CO₂ saturated solutions of polyethylene glycols (PEGs) of different molecular weight at different pressures and at a temperature of 343 K was measured using a high pressure view cell. Also a temperature impact on the viscosity of pure PEGs was observed at ambient pressure. After saturating PEG 1500 with 10 MPa of CO₂ pressure its viscosity decreases from 76.6 mPa s to 2.24 mPa s at 333 K. Further addition of CO₂ and increasing the pressure results in even lower viscosity and the highest viscosity reduction was reached at the highest pressure; at 35 MPa viscosity of the system PEG 1500/CO₂ is only 0.665 mPa s.     

Separation of a reaction mixture of ethyl acetate production via ethanol dehydrogenation

The simulation of phase equilibrium in a multicomponent reaction system of ethanol dehydrogenation process has been performed. The structure of the distillation diagram of this system has been found and its evolution during changes in pressure has been studied. An analysis of the diagram properties has made it possible to define the range of values of the operating parameters that allow for the separation of the reaction mixture in order to propose a structure of technological separation system and to carry out its parametric optimization.