Ethylene carbonate capacity measurements

A few measurements have been reported for ethylene carbonate, propylene carbonate, 4-butyrolactone and 4-valerolactone. ° These compounds are aprotic 5-membered heterocylic ring structures with unusually large dipole moments. Dielectric constants range from 36 for valerolactone to 89.6 for ethylene carbonate. All appear to be normal polar liquids. In all four solvents a capacity hump is observed on the positive side of the pzc (Fig. 7.2.5). The temperature coefficient of capacity at the hump in the butyrolactone solution is only one third of its value in DMSO and sulpholane, and less than one tenth of the water value. Anions appear to be specifically adsorbed as in other solvents. Strong specific adsorption of CIO4 anions from propylene carbonate has been reported. Butyrolactone is strongly adsorbed from aqueous solutions. ... 

Freshly distilled carbon tetrachloride (210 g, 1.36 moles), water (35 g), and benzoyl peroxide (0.47 g, 0.00194 mole) are placed in a stainless steel autoclave (capacity about 350 ml) fitted with a gas-inlet tube and a thermoelement for temperature measurement. Air is removed from the autoclave, and ethylene is pressed in to 35 atm. The autoclave is then shaken in a horizontal position and heated when the temperature of the mixture reaches 70°, more ethylene is pressed in, to give a pressure of about 100 atm. The mixture is then kept at 95° for 5 h, more ethylene being pressed in to keep the pressure at 85-100 atm. Finally the autoclave is cooled and the product is removed, separated from the water, and dried over anhydrous magnesium sulfate. After unchanged carbon tetrachloride has been distilled off, fractionation of the telomer gives the following yields ... 

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