Synthesis Of Glycol Ether And Study On Phase Diagram Of Its Aqueous Solution

In this paper, Two methods of the etherified end capped glycol ethers are synthesised. One is the etherified end capped glycol ethers are synthesised by Williamson, which are both have hydrophobic and hydrophilic structures.The other is the etherified end group capped glycol ethers are synthesised by the reaction of polyethylene glycol oligomer and bromoalkanes. Their structures were identified by 1H-NMR, 13C-NMR and IR. The two-phase equilibrium systems of ethylene glycol monobutyl ether-water and ethylene glycol monobutyl ether-sodium chloride aqueous solution are researched. With the temperature increasing, the hydrophobic of ethylene glycol monobutyl ether shows an increasing stronger. When the temperature at 80℃, the content of ethylene glycol monobutyl ether above 70% in organic phase; and less than 10% in water phase.The use of turbidity titration, The three-phase equilibrium systems of ethylene glycol monobutyl ether-cyclohexane-water, diethylene glycol monobutyl ether-cyclohexane-water, ethylene glycol monobutyl ether-sodium chloride-water and tetraethylene glycol dimethyl ether-sodium sulfate-water are researched. The tie lines are determined by using gas chromatography and conductivity method. Drawing the phase diagrams according to the experimental data at different temperatures.The phase diagrams of the ethylene glycol monobutyl ether-cyclohexane-water, which are measured at 20℃, 30℃ and 40℃. With the temperature increasing, the two-phase region and the slope of tie line are larger. So temperature is the important condition for the two-phase to separate. But the phase diagrams of the diethylene glycol monobutyl ether-cyclohexane-water, which are measured at 10℃, 20℃, 30℃ and 40℃. The results are exactly oppposited.For the ether-water-salt systems, expression of the phase diagrams with rectangular plot are often more intuitive to understand. which are measured at 20℃, 30℃ and 40℃. The tie lines are determined by using conductivity method. With the temperature increasing, the two-phase region of the ethylene glycol monobutyl ether-sodium chloride–water is gradually increased, and the system of tetraethylene glycol dimethyl ether-sodium sulfate-water is also increased, but the increasing of two-phase region is not obviously.