Thermodynamic study of (alkyl esters+α,ω-alkyl dihalides) III. for 20 binary mixtures {xCu−1H2u−1CO2C4H9+(1−x)α,ω-ClCH2(CH2)v−2CH2Cl}, where u=1 to 4, α=1 and v=ω=2 to 6

Thermodynamic study of (alkyl esters+α,ω-alkyl dihalides) V. for 25 binary mixtures {xCu−1H2u−1CO2CH3+(1−x)α,ω-ClCH2(CH2)v−2CH2Cl}, where u=1 to 5, α=1 and v=ω=2 to 6

“…Hence, in figure 3a and b, respectively, showing equimolar values of H E m and V E m , it can be observed that, as the acid u chain of the methyl ester increases in length, the mixtures become less endothermic, see figure 3a. In contrast, for each ester the mixing enthalpy increases with the value of v. An explanation for the global behaviour would be similar to that given in previous studies [1,2] although some specific aspects can be mentioned. In figure 3a, the values of H E m are compared at intermediate concentration for the same a,x-dichloroalkanes, for the methyl and butyl esters [2].…”

“…Figure 2a to e shows the experimental data of V E m for the same set of mixtures studied here; but in this case, there are no data in the literature to use for comparative purposes. Figure 3a and b represents, respectively, the equimolar values of both excess quantities, H E m and V E m , together with those obtained in a previous work [2] corresponding to the same binary systems but with butyl esters.…”

“…In all cases, the k parameter are used as fixed amounts, depending on the property of the mixture to be correlated and calculated as described in detail below. Hence, to correlate the pairs ðx; V E m Þ this parameter is calculated as the quotient of molar volumes at the same working temperature [1,2,11]…”

“…In previous articles [1,2] values of H E m enthalpies and excess volumes V E m were presented for mixtures of ethyl and butyl esters with five a,x-dichloroalkanes, in an attempt to interpret the specific behaviour of these mixtures. From the results obtained, some conclusions were proposed revealing the existence of a set of different effects during the mixing process, even the presence of opposite effects in the dynamic of one specified mixture due to intra and/or intermolecular effects, appears to be evident.…”

“…Hence, for mixtures of ethyl esters [1] application of the UNIFAC model using the versions of Dang and Tassios [4] and Gmehling et al [5] produce totally unsatisfactory estimations. In a recent article [2], with mixtures of butyl esters, a global parameter was obtained for the ester/chloride interaction that gave place to substantially better predictions of enthalpies than by using the original parameters of Dang and Tassios [4]. Since there are no data in the literature of other thermodynamic quantities for these mixtures, the recalculus was not done using the version of Gmehling et al [5].…”