Intermolecular potential model parameters for cyclic ethers and chloroalkanes in the SAFT-VR approach

The SAFT approach for attractive potentials of variable range (SAFT-VR) has been used to model four cyclic ethers: 1,3-dioxolane, 1,4-dioxane, tetrahydrofuran and tetrahydropyran, and six chloroalkanes: 1-chloropropane, 2-chloropropane, 1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane and 2-chloro-2-methylpropane. The molecules are represented as chains of m tangentially bonded spherical segments interacting via square-well potentials of variable attractive range. The square-well segments are characterised by a hard-core diameter σ, a well depth ɛ and a range λ. For each compound, the optimised values of the intermolecular model parameters m, σ, ɛ and λ are obtained by comparison to experimental vapour pressure and saturated liquid density data. Although all the compounds examined are highly polar, we find that the SAFT-VR approach is capable of providing a good description of the phase behaviour without the need to take into account polar interactions explicitly. The largest errors found are of the order of 2%, both for the pressure and for the density. In future work the models presented here will be used to treat mixture phase behaviour.