HBIDPIHSE EOglUglIIA ELSEVIER Fluid Phase Equilibria 133 (1997) 187-192 Excess molar volumes of 1-propanol + n-polyethers at 298.15 K A. Serna, I. Garcia de la Fuente *, J.A. Gonzfilez, J.C. Cobos Departamento de Termodindmica y Fisica Aplicada, Universidad de Valladolid, E-47071 Valladolid, Spain Abstract Excess molar volumes VE at 298.15 K and atmospheric pressure for l-propanol + 2,5-dioxahexane, 3,6-dioxaoctane, 2,5,8-trioxanonane, 3,6,9-trioxaundecane or 5,8,11-trioxapentadecane have been calculated from densities measured with an Anton-Paar DMA 602 vibrating-tube densimeter. All the excess molar volumes are negative over the whole mole-fraction range, nearly symmetrical for mixtures with diethers and slightly skewed towards the region of high mole fraction of 1-propanol for mixtures with triethers. The value of Vm E decreases as the n-alkyl chain end length of the diethers or the triethers increases. When the n-alkyl chain end of the polyethers is the methyl group (-CH3), V E is very small in absolute value and similar for the diethers and triethers, whereas when the end group is larger than the methyl group, the value of Vm E is more negative for the diethers than for the triethers. These results, together with previously published excess molar enthalpies, suggest the formation of hydrogen bonds between the functional group -OH of the 1-alkanol and the -O- atoms of the polyethers. © 1997 Elsevier Science B.V. Keywords: Excess molar volume; Associated mixtures; Polarity; 1-Propanol; n-Polyethers 1. Introduction As a part of our studies on binary mixtures containing the oxygen (-O-) and hydroxyl (-OH) functional groups [1-14], we report here experimental excess molar volumes Vm E over the whole mole-fraction range at atmospheric pressure and 298.15 K for mixtures containing 1-propanol with 2,5-dioxahexane, 3,6-dioxaoctane, 2,5,8-trioxanonane, 3,6,9-trioxaundecane or 5,8,11-trioxapentade- cane. The aim of this work is to provide results for the characterization of the influence of the size, shape and polarity of the ether on the thermodynamic properties of this type of mixture when we pass from a molecule with one -O- functional group to a molecule with several -O- functional groups. * Corresponding author. 0378-3812/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PH S0378-3812(97)00020-4