Gas-liquid critical temperatures of mixtures containing an organosilicon compound

Abstract

The gas-liquid critical temperatures of 16 binary mixtures containing an organosilicon compound have been measured by the sealed-tube method, together with the gas-liquid critical temperature and pressure of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane.   

The results for the mixtures have been used to calculate a parameter characterizing the interactions between unlike molecules. An iterative solution to the criticality condition was used together with the one-fluid model and a 'hard sphere+attractive term' equation of state.    

The interaction parameters are discussed briefly. The one-fluid model in the form used here, at least, appears to be unsatisfactory for predicting the composition dependence of the gas-liquid critical temperatures within 5 K for mixtures of molecules of widely differing sizes (i.e. size ratios as estimated from molar volumes of greater than 1 : 4).