Thermodynamics of mixing of ethylene oxide oligomers with different end groups in tetrachloromethane: theoretical treatment

In a previous paper we reported the enthalpies of mixing of oligomers of ethylene oxide with different end groups in tetrachloromethane. This paper shows the applicability of the modified theoretical treatment, based on a quasichemical equilibrium of the contacting segmental surfaces originated from Huggins, to our experimental results. The experimental data of ethylene oxide oligomers with methoxy end groups can be described with the energy parameter Δε_αβ, the equilibrium constant K_αβ and the surface ratio r_σ assuming a chemically uniform surface of the oligomer in CCI₄. Ethylene oxides with strong polar OH end groups can be treated successfully with an extended version of the theory with two additional parameters K and ΔΔε for systems containing three different kinds of chemical units.