醇类液体的热压力系数及内压

Thermal Pressure Coefficient and Internal Pressure for Alcohol Liquids

本文测定25～85℃温度范围内正戊醇、正己醇、正庚醇和正辛醇的热压力系数,发现这些醇类液体的内压几乎不随温度而变.本文还将修正的van der Waals模型推广到了醇类液体,与非缔合液体一样,它们的排斥体积亦与密度呈线性关系.但是,模型参数之比B/A^2不再是个常数,而是随醇分子中碳原子数的增多而快速地减小,这个比值可作为自缔合能力的一种量度.

The thermal pressure coefficients of liquids for 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol have been measured over the temperature range of 25-85℃. It is found that their internal pressures don't almost vary with temperature. The modified van der Waals model is applied to the alcohol liquids. As non-associating liquids, their excluded volume can also be expressed as a linear function of density. However, the ratio of the model parameters, B/A2 is nota constant and decreases speedily with increase of the number of carbon atoms in the alcohol molecule. This ratio may be considered as a measure of the ability of self-association for alcohols.