Ethyl acetate solubility parameter

The solubility of commercial poly(methyl methacrylate) is consistent with that expected of an amorphous thermoplastic with a solubility parameter of about 18.8 MPa. Solvents include ethyl acetate (8 = 18.6), ethylene dichloride (8 = 20.0), trichloroethylene (8 = 19), chloroform (8 = 19) and toluene (8 = 20), all in units ofMPa. Difficulties may, however, occur in dissolving cast poly(methyl methacrylate) sheet because of its high molecular weight. 

Triphenyl phosphate is a crystalline solid which has less compatibility with the polymer. This may be expected from solubility parameter data. It is often used in conjunction with dimethyl phthalate and has the added virtues of imparting flame resistance and improved water resistance. It is more permanent than DMP. Triacetin is less important now than at one time since, although it is compatible, it is also highly volatile and lowers the water resistance of the compound. Today it is essential to prepare low-cost compounds to allow cellulose acetate to compete with the synthetic polymers, and plasticisers such as ethyl phthalyl ethyl glycollate, which are superior in some respects, are now rarely used. 

Of the instances of so-called solvent cracking of amorphous polymers known to the author, the liquid involved is not usually a true solvent of the polymer but instead has a solubility parameter on the borderline of the solubility range. Examples are polystyrene and white spirit, polycarbonate and methanol and ethyl acetate with polysulphone. The propensity to solvent stress cracking is however far from predictable and intending users of a polymer would have to check on this before use. 

Another important use of solubility parameters is in interpreting the effects of different solvents on the rates of reactions. In a chemical reaction, it is the concentration of the transition state that determines the rate of the reaction. Depending on the characteristics of the transition state, the solvent used can either facilitate or hinder its formation. For example, a transition state that is large and has little charge separation is hindered in its formation by using a solvent that has a high value of S. The volume of activation is usually positive for forming such a transition state which requires expansion of the solvent. A reaction of this type is the esterification of acetic anhydride with ethyl alcohol ... 

Unavailable because experimental methods for estimation of this parameter for aliphatic esters are lacking in the documented literature. Based on its solubility values, adsorption of ethyl acetate is not expected to be significant. 

Generally, one can say that parameters obtained from VLE should be used only for qualitative calculations. The result is considerably improved if the parameters for the binary ethyl acetate-water are calculated from solubility data. 

From Hildebrand s solubility parameter, heptane is less polar than toluene, which in turn is less polar than methylene chloride, etc., to water, the most polar. Unfortunately, toluene and ethyl acetate exhibit similar 8 which does not account for their chemical properties moreover, Hildebrand s solubility parameters are not known for mixtures. 

Besides showing the usefulness of the solubility parameter for the quantification of polarity, table 2.2 also illustrates the shortcomings of the model. On the basis of its solubility parameter alone, methylene chloride will be expected to behave quite similar to dioxane, and toluene similar to ethyl acetate. However, in both cases there are considerable differences between the solvents in practice. For example, dioxane is miscible with water in all proportions, while methylene chloride is virtually insoluble in water. Clearly, to account for differences in behaviour between compounds of similar polarity a refinement of the model is needed. 

Based on the ranking of solubility parameter differences, A8, ethanol would be the most soluble followed by acetone and then ethyl acetate. This is what we would expect based on the complete miscibility of ethanol in water. 

Ethyl acetate is the most soluble solvent in the plastic based on having the smallest A8 with LDPE. Note that the solubility of these solvents in OPP will not differ greatly from LDPE based on the similar average solubility parameters between OPP and LDPE (17.8 vs. 16.5). 

The Wilson parameters used for the VAc-H O pair are assumed to be the same as the parameters for ethyl acetate and water. The reason for this assumption is that no VLE data are presented in DECHEMA for vinyl acetate and water, but ethyl acetate and vinyl acetate are quite similar species and should behave essentially identically. The liquid-liquid equilibrium solubility data for the VAc-H20 pair in the column decanter come from Smith (1942) extrapolated to the decanter temperature of 40°C. 

The CMC of the surfactant in the aqueous phase is changed very little by the presence of a second liquid phase in which the surfactant does not dissolve appreciably and which, in turn, either does not dissolve appreciably in the aqueous phase or is solubilized only in the inner core of the micelles (e.g., saturated aliphatic hydrocarbons). When the hydrocarbon is a short-chain unsaturated, or aromatic hydrocarbon, however, the value of the CMC is significantly less than that in air, with the more polar hydrocarbon causing a larger decrease (Rehfeld, 1967 Vijayendran, 1979 Murphy, 1988). This is presumably because some of this second liquid phase adsorbs in the outer portion of the surfactant micelle and acts as a class I material (Section C). On the other hand, the more polar ethyl acetate increases the CMC of sodium dodecyl sulfate slightly, presumably either because it has appreciable solubility in water and thus increases its solubility parameter, with consequent increase in the CMC of the surfactant, or because the surfactant has appreciable solubility in the ethyl acetate phase, thus decreasing its concentration in the aqueous phase with consequent increase in the CMC. 

For the UNIQUAC equation, there are two adjustable equation parameters for each binary. For the binary that is partially miscible, the best way to determine the two binary parameters is to fit the mutual solubility data. For the completely miscible binaries, useful interaction parameters can be obtained from vie data. However, fitting vie data to within experimental accuracy does not uniquely determine the binary parameters. The choice of a particular set of parameters can have a significant effect on the representation of the ternary lie. For the ternary system of chloroform, water, and acetone at 333°K, for example, the two binary parameters are first determined from mutual solubility data for chloroform and water and then the other binary parameters for the two miscible binaries. Somewhat improved predictions occur by fitting binary parameters to the miscible binaries. Similar predictions have also been found for ternary systems of ethyl acetate, ethanol, and water. 

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. Paracetamol is obtained as large monoclinic prisms obtained from water having mp 169-170.5°C, and has a slightly bitter taste. It shows 1.293 Mfjnax (ethanol) 250 nm (g 13800). It is found to be very slightly soluble in cold water and considerably more soluble in hot water soluble in methanol, ethanol, DMF, ethylene dichloride, acetone, ethyl acetate slightly soluble in ether and almost insoluble in petroleum ether, pentane and benzene. 

Physical Parameters. Flopropione is obtained as monohydrate needles from water. The anhydrous compound has mp 175-176°C. It is found to be soluble in ethanol, ether, ethyl acetate, hot water and very slightly soluble in cold water. 

S Physical Parameters. The crystals of clotrimazole has mp 147-149 C. It is a weak base, slightly soluble in water, benzene, toluene soluble in acetone, chloroform, ethyl acetate and DMF. It gets hydrolysed rapidly upon heating in aqueous acids. 

FIGURE 5.9 Dependence of the rate constants for the reaction between acetic anhydride and ethyl alcohol on the solubility parameters of the solvents. (Constructed using rate constants given by Laidler (1965).)... 

The viscosity method for soluble polymers and the swelling method for cross-linked network polymers yield quite unambiguous values for polymer solubility parameters, so long as one is confined to a series of structurally similar solvents. For example, the data in Figure 6-1 apply to aliphatic hydrocarbons as well as to long-chain esters and ketones. Cycloaliphatic hydrocarbons and short-chain esters such as ethyl acetate deviate significantly from the curves shown. 

Figure 3.27 Dependence of equilibrium swelling on the solubility parameter in a number of solvents (I) diethyl ether (11) diethylene glycol diethyl ether (III) butyl acetate (IV) ethyl acetate (V) tetrahydrofdran (VI) dioxane. Polyurethane networks based on PTMG and PPG mixture without additives (4) and containing various KEP-2 mass fractions (1) 1.5 x 10 (3) 5 X 10- (2) 7.5 X 10- (5) 1.5 x 10 ...

An amorphous polymer, PMMA has a solubility parameter of about 18.8 MPaX and is soluble in a number of solvents with similar solubility parameters. Solvents include ethyl acetate (8 18.6 MPa)0, ethylene dichloride (8 20.0 MPa, trichloroethylene (8 19 MPaX), chloroform (8 19 MPa>0, and toluene (8 20 MPaX). The polymer is attacked by mineral acids but is resistant to alkalis, water and most aqueous inorganic salt solutions. A number of organic materials although not solvents may cause crazing and cracking (e.g. aliphatic alcohols). 

Another method involves excimer fluorescence as a molecular probe see Section 2.9. The question may be raised as to whether polymer blends will become more miscible if the differences in their solubility parameters are reduced. Excimer fluorescence provides some evidence see Rgure 4.14 (52). Here, 0.2 wt.% of poly(2-vinyl naphthalene), P2VN, is dispersed in a series of poly (alkyl methacrylates). These include the following, which are identified in Figure 4.14 by acronym methyl, PMMA ethyl, PEMA n-propyl, PnPMA isopropyl, PiPMA n-butyl, PnBMA isobutyl, PiBMA . yec-butyl, PsBMA ferf-butyl, PtBMA phenyl, PPhMA, isobomyl, PiBoMA benzyl, PBzMA and cyclohexyl, PCMA. Two other host polymers were polystyrene, PS, and poly(vinyl acetate), PVAc. 

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