Vapour pressures and critical points of liquids. Glycols and cyclic diols.
Abstract:(Scanned original: to be superseded.)
ESDU 95002 presents vapour pressure data for 22 glycols and 6 cyclic diols (molecules from C2 to C6). The data were obtained by a critical evaluation of experimental results in the literature. The data available were limited but using a correlation previously developed relating the behaviour of the coefficients of the Wagner vapour pressure equation to the latent heat of vaporisation and the compression factor it was possible to extrapolate the data. The Wagner equation was used over a temperature range from close to the melting point to about 0.9 of the critical temperature, although for the cyclic compounds it is extended to close to the critical point. The coefficients of the equation are given and two tables of vapour pressure calculated using them are included; in SI units at 5 K intervals and in mm of mercury or atmospheres (for the higher values) at 5 degree Celsius intervals. A table also gives the saturation temperature at various specified pressures and indicates the possible uncertainty in the calculated values. Also given are values of acentric factor, normal melting point, normal boiling point and the slope of the saturation temperature v vapour pressure curve at the normal boiling point. The sources of data for each compound are listed. Density data for the compounds (except pentane-2,4-diol, hexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol and benzene-1,4-diol) appear in ESDU 95003, and the choice of critical point values gave the best correlations for both vapour pressure and density.
|Data Item ESDU 95002|