Excess molar volumes of binary mixtures of 1-heptanol or 1-nonanol with n-polyethers at 25 degrees C

Excess molar volumes V-m(E) at 25 degrees C and atmospheric pressure over t he entire composition range for binary mixtures of 1-heptanol with 2,5-diox ahexane, 2,5,8-trioxanonane, 5,8,11-trioxapentadecane, 2,5,8,11-tetraoxadod ecane, or 2,5,8,11, 14-pentaoxapentadecane, and mixtures of 1-nonanol with 2,5-dioxahexane, 3,6-dioxaoctane, 2,5,8-trioxanonane, 3,6,9-trioxaundecane, 5,8,11-trioxapentadecane, 2,5,8,11-tetraoxadodecane, or 2,5,8,11,14-pentao xapentadecane are reported from densities measured with a vibrating-tube de nsimeter. V-m(E) curves are nearly symmetrical at about 0.5 mole fraction. Excess molar volumes are usually positive, indicating predominance of posit ive contributions to V-m(E) from the disruption of H bonds of alcohols and from physical interactions. When chain lengths of both components of the mi xture are increased, the contribution from interstitial accommodation appea rs to be sufficiently negative, such that V-m(E) becomes negative (e.g., 1- nonanol + 5,8,11-tetraoxapentadecane).