1-pentanol solubility parameter

As shown in Figure 2, the rate of SAN copolymerization in the presence of ZnCl2 is solvent dependent. The greatest rates of polymerization were noted in 1-pentanol (solubility parameter 6=10.9 H) and tert.-butyl alcohol (6=10.6 H). The rates were correspondingly slower in less polar 1-octanol (6=10.3 H), and in more polar 1-butanol (6=11.4 H) and 1-propanol (6=11.9 H). PSAN swells slightly in 1-octanol, but is insoluble in the other alcohols. Presumably the optimum solubility parameter range 10.6-10.9 H (the solubility parameters of 1-pentanol and tert.-butyl alcohol) corresponds to the optimum solvency of the CTC and the optimum minimum solvation of the copolymer. The slower rates in 1-butanol and 1-propanol, both poor solvents for the copolymer, are probably due to the inability of the polarized CTC to penetrate the non-polar macroradical coil. The slower rate of... 

Paine et al. [85] extensively studied the effect of solvent in the dispersion polymerization of styrene in the polar media. In their study, the dispersion polymerization of styrene was carried out by changing the dispersion medium. They used hydroxypropyl cellulose (HPC) as the stabilizer and its concentration was fixed to 1.5% within a series of -alcohols tried as the dispersion media. The particle size increased from only 2.0 /itm in methanol to about 8.3 /itm in pentanol, and then decreased back to 1 ixm in octadecanol. The particle size values plotted against the Hansen solubility parameters... 

As already mentioned, in evaluating the dispersive component of the solubility parameter in the literature, reference is usually made to the homomorph concept. The homomorph is typically the hydrocarbon with the structure closest to the studied substance. The homomorph of n-pentanol, for example, is n-hexane and of isopropanol is isobutane. The homomorph concept may be used with the present approach as well. Equation 2.36 indicates how to use it The homomorph and the studied substance should be brought at the same reduced density — a type of corresponding states. Table 2.5 also includes the calculated homomorph component, 8, of the solubility parameter. 

The dielectric constant is governed by the ease of formation of dipoles under the influence of electric forces in the solvent. The molecular weight is therefore not expected to have an effect on the dielectric constant but the polarity of the product, as expressed by its Hildebrand solubility parameter and fractional polarity (for more detail see chapter on solvent power), have a pronounced influence. This is demonstrated by the homologous series of -alcohols, where the solubility parameter and fractional polarity decrease from 14.5 and 0.388 respectively for methanol to 10.9 and 0.074 for -pentanol. A few examples taken from the second series are shown in Table 2.9. 

It is well known that the aqueous phase behavior of surfactants is influenced by, for example, the presence of short-chain alcohols [66,78]. These co-surfactants increase the effective value of the packing parameter [67,79] due to a decrease in the area per head group and therefore favor the formation of structures with a lower curvature. It was found that organic dyes such as thymol blue, dimidiiunbromide and methyl orange that are not soluble in pure supercritical CO2, could be conveniently solubihzed in AOT water-in-C02 reverse microemulsions with 2,2,3,3,4,4,5,5-octafluoro-l-pentanol as a co-surfactant [80]. In a recent report [81] the solubilization capacity of water in a Tx-lOO/cyclohexane/water system was foimd to be influenced by the compressed gases, which worked as a co-surfactant. 

Of course, all the calculations here are approximate. In particular, we have used UNIFAC, which is not meant to be applicable to liquid-liquid equilibrium, and further, —25°C is below the temperature at which the UNIFAC parameters were obtained, so. the results we have obtained are not expected to be accurate. Therefore, all the conclusions should be checked against experimental data. As examples of the uncertainty of such predictions, from experimental data it is found that the amount of ethylene glycol required to result in a mixture freezing point of —25°C is closer to 45 wt % than the - 57 wt % estimated here, and that -pentanol is actually only soluble in water to about 2 j wt %, rather than the complete miscibility found here. This should serve as a warning concerning the use of any completely predictive method, even the UNIFAC model, which is currently the best. 

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