کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
217254 | 1426325 | 2007 | 16 صفحه PDF | دانلود رایگان |

The experimental data of excess molar enthalpies HmE and excess molar volumes VmE are presented for a set of 25 binary mixtures comprised of the first five methyl esters Cu−1H2u −1COOCH3 (u = 1 to 5) and five α,ω-dichloroalkanes, ClCH2(CH2)v−2CH2Cl (v = 2 to 6), obtained at a temperature of 298.15 K and atmospheric pressure. Except for the mixtures with u = 1 and v = 2 to 6, which are all endothermic and with u = 5 and v = 2 to 6, which are all exothermic, the others present net endo/exothermic effects and these mixing effects evolve quasiregularly, from endothermic to exothermic, depending on the dichloroalkane present. However, the VmE are positive in most mixtures except for those corresponding to u = 4, 5 and v = 5, 6, which present contraction effects. These results indicate a set of specific interactions with simultaneous effects for VmE of expansion/contraction and for exothermic/endothermic HmE for this set of mixtures. The change in VmE with the chain length of the compounds is irregular.To achieve a good application of the UNIFAC model using the version of Dang and Tassios, parameters of the ester (G)/dichloride (G′) interaction were calculated again, making a distinction, during its application, dependent on the acid part of the ester u. Hence, interaction parameters are presented as a function of u, and of the dichloroalkane chain length v. The most appropriate general expression was of the type:aG/G′=φ(u,v)=∑i=0nai-1ui-1+∑i=0nbi-1vi-1and with this proposal good estimations of enthalpies were obtained with the UNIFAC model.
Journal: The Journal of Chemical Thermodynamics - Volume 39, Issue 5, May 2007, Pages 742–757