Excess enthalpy of the system propan-1-ol plus MTBE plus i-octane. Experimental results and ERAS model calculations

Molar excess enthalpies H-E of the liquid mixture propan-1-ol + methyl-t-bu tylether (MTBE) + 2,2,4-trimethylpentane (i-octane) have been measured by f low calorimetry including the three binary systems. The values obtained are endothermic in the whole range of ternary composition. The results can be explained by the strong hydrogen bonds existing between the alcohol molecul es which are broken upon mixing. Also, cross-association between propan-1-o l and MTBE plays a significant role, The ERAS-model has been used for descr ibing the experimental results. The model parameters adjusted to the three binary systems provide equilibrium constants and association enthalpies for the cross-association between propan-1-ol and MTBE. Results predicted by t he ERAS-model in the ternary mixture describe the experiments in a satisfyi ng way without adjusting ternary parameters. (C) 1999 Elsevier Science B.V. All rights reserved.