Ethers binary azeotropes with

Isoprene [78-79-5] (2-methyl-1,3-butadiene) is a colorless, volatile Hquid that is soluble in most hydrocarbons but is practically insoluble in water. Isoprene forms binary azeotropes with water, methanol, methylamine, acetonitrile, methyl formate, bromoethane, ethyl alcohol, methyl sulfide, acetone, propylene oxide, ethyl formate, isopropyl nitrate, methyla1 (dimethoxymethane), ethyl ether, and / -pentane. Ternary azeotropes form with water—acetone, water—acetonitrile, and methyl formate—ethyl bromide (8). Typical properties of isoprene are Hsted in Table 1. 

The physical piopeities of ethyl chloiide aie hsted in Table 1. At 0°C, 100 g ethyl chloride dissolve 0.07 g water and 100 g water dissolve 0.447 g ethyl chloride. The solubihty of water in ethyl chloride increases sharply with temperature to 0.36 g/100 g at 50°C. Ethyl chloride dissolves many organic substances, such as fats, oils, resins, and waxes, and it is also a solvent for sulfur and phosphoms. It is miscible with methyl and ethyl alcohols, diethyl ether, ethyl acetate, methylene chloride, chloroform, carbon tetrachloride, and benzene. Butane, ethyl nitrite, and 2-methylbutane each have been reported to form a binary azeotrope with ethyl chloride, but the accuracy of this data is uncertain (1). 

Dicbioromethane, Methylene Chloride or Methylene Dichloride (called Dichlormethan or Methylenchlorid in Ger), CH2CI2, colorless, mobile liq having a pleasant ethereal odor, fr p -96.7°, bp 40.4°, d 1.326 at 20°, nD 1.4246 at 20°(liq), Qcomb 144.5 keal/mol expl limits in O2 15.5-66% by vol forms binary azeotropes with many solvs can be... 

Liquid with pungent odor. bp7 81.4. tig 1.4086. dj 0.8636 dj5 0 8407. Easily soluble in water, methanol, ethanol, ether, acetone, glacial acetic acid. Slightly sol in hydrocarbons. Forms a binary azeotrope with water, bp 75 (12% water), uv spectrum and electric moments Rogers, J. Am. Chem. Soc. 69, 2544 (1947). Polymerizes on standing, LDm in mioe and rats 35 mg/kg, C.A. 72, 124809b 0970). 

As an example, the separation of a butene/methanol/MTBE system is investigated. Methyl tertiary-butyl ether (MTBE) is the desired product, and hence needs to be efficiently recovered from a reactor output. Difficulty arises when separating such a mixture with conventional distillation processes, because of the binary azeotropes that exist between methanol and MTBE, as well as between methanol and butene. The driving force for separation in membrane processes differs from that in distillation, thus a membrane process will not exhibit the same azeotropic behavior. Thus, the limitations on distillation processes can be overcome by using a membrane unit. 

The best solvents for hexaorganodisiloxanes are benzene, diethyl ether and chloroform. Their solubility in petroleum ether, acetone and alcohols is only moderate, so that these solvents can be used for recrystallization. The hexaorganodisiloxanes have a remarkable tendency to form binary and tertiary azeotropic mixtures with organosilanols and solvents, and these are difficult to separate by distillation. 

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