Carbon tetrachloride solubility parameter

Tables 5.4 and 5.5 predict that unvulcanised natural rubber (8 = 16.5) will be dissolved in toluene (8 = 18.2) and in carbon tetrachloride (8 = 17.5) but not in ethanol (8 = 26.0), all values being in units ofMPa. This is found to be true. Similarly it is found that there is a wide range of solvents for polystyrene in the solubility parameter range 17.2-19.7 MPa. ...

FIGURE 3 2 Solvent extraction efficiencies (EF) as functions of dielectric constants (D), solubility parameters (6), and polarity parameters (P and E -). Solvents studied silicon tetrachloride, carbon disulfide, n pentane. Freon 113, cyclopentane, n-hexane, carbon tetradiloride, diethylether, cyclohexane, isooctane, benzene (reference, EF 100), toluene, trichloroethylene, diethylamine, chloroform, triethylamine, methylene, chloride, tetra-hydrofuran, l,4 dioxane, pyridine, 2 propanol, acetone, ethanol, methanol, dimethyl sulfoxide, and water. Reprinted with permission from Grosjean. ... 

FIGURE 2.2 Regularsolutiontheory plotfor hydrocortisone solubility data. The curve represents thesolubility predicted by Equation 2.41 using data frorhexane, cyclohexane, carbon tetrachloride, toluene, and benzene to estimate the solubility parameter of hydrocortisone. (Data taken from Hagen, T. A. 1979. With permission of the author.)... 

In an engineering analysis, the solubility parameter and liquid volume are needed for carbon tetrachloride (CCI4). Determine the solubility parameter and liquid volume for carbon tetrachloride. 

As the data in Table 4.3 show, the solubility parameter reflects how a chemist might rank these solvents in terms of polarity, e.g. water as the most polar (highest 5) and hexane as the least polar (lowest 8) but also one of the difficulties with this measurement of polarity is highlighted. The solubility parameter suggests that tetrahydrofuran (THE) and carbon tetrachloride are very similar even though carbon tetrachloride is immiscible with water whilst THE is miscible with water in all proportions. A similar comparison may be made between chloroform (8 = 19.1, water-immiscible) and acetone (8 = 20.2, water-miscible). 

A pump capable of several thousand p.s.i. commonly is used. Not only is the pump needed to maintain supercritical conditions, but the solubilizing power of the system varies greatly with pressure, usually dissolving more solutes as the pressure increases. For example, COj at 1.23 g/em will dissolve eompounds with Hildebrand s solubility parameter (Chapter 41, p. 479) from 7-10, about the same as benzene, chloroform, ethyl acetate, acetone, cyclohexane, carbon tetrachloride, toluene, ethyl ether, and pentane. If the pressure is reduced so that the COj is about 0.9 g/cm then it will dissolve compounds with parameters from 7-9 (solvents like cyclohexane, carbon tetrachloride, toluene, ethyl ether, and pentane) and if further lowered to 0.6 g/cm, it will dissolve only compounds with parameters of 7-8 (ethyl ether and pentane). 

Physical Parameters. Povidone-iodine is obtained as yellowish-brown, amorphous powder with slight typical characteristic odour. The aqueous solutions have a pH 2 it may be made more neutral (but less stable) by the addition of sodium bicarbonate. It is fomid to be soluble in ethanol and water almost insoluble in chloroform, carbon tetrachloride, solvent ether, hexane and acetone. Interestingly, its solutions do not respond to the familiar blue colouP starch-test, when prepared even fi-eshly. 

Thus where Hildebrand s equation is valid, if a polymer and a solvent have similar solubility parameters then solution will occur. Such validity covers amorphous hydrocarbon rubbers and can also be used qualitatively with caution with the more polar rubbers. The solubility parameter of natural rubber, in (MJ/m ) is 16-5 which suggests that a not too entangled mass of rubber molecules will dissolve in turpentine (16-5), carbon tetrachloride (17-6) and toluene (18-2) but not in acetone (20-4) or ethanol (26-0). (All figures are expressed in units of (MJ/m )". ) This expectation is realized in practice. 

The plots (or their simpler two-dimensional form, which is a plot of /h vs /p, in effect assuming/ to be invariant) have considerable practical utility in solvent selection (Burke 1984). The solubility of a polymer is often achieved using a mixture of solvents. As a general rule, a mixture of solvents will dissolve a polymer if the solubility parameter of that mixture lies close to that of a known good solvent for the polymer. In designing mixed solvent systems the Teas plot allows the solubility characteristics of solvent mixtures to be predicted to some extent. In Fig. 2.3, the solvents carbon tetrachloride (CCI4) and methanol (CH3OH) are clearly nonsolvents for poly(methyl methacrylate)... 

The highest losses in mechanical properties of a polymer take place when the solubility parameters of a polymer and solvent match. The same statement can be made when the polarities of a solvent and a primary polymer bond match. A close match of the solubility parameters or polarities results in the incompatibility of the polymer and the solvent. To be clear, incompatible here means that the solvent attacks the polymer. Selection of a polymer for a given chemical environment must be made by evaluating the materials that have the largest solubility differences or polarity differences with the chemical environment. For example nylon 6/6 resists cleaning solvents such as carbon tetrachloride, and polystyrene and ethylene glycol are incompatible. Nylon 6/6 has polar amide bonds, while carbon tetrachloride is a non-polar solvent. In comparison, water is a polar liquid and is absorbed by nylon 6/6. Similarly polystyrene and ethylene glycol are both polar, and thus interact. 

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