Interaction parameters and the equilibrium cationic polymerization of tetrahydrofuran in benzene

Abstract

Flory–Huggins interaction parameters, χ₁₂, have been determined for tetrahydrofuran–benzene, benzene–polytetrahydrofuran and tetrahydrofuran–polytetrahydrofuran mixtures from static vapour-pressure measurements. Values of χ lie between –0.18 to –0.23 for the first system in the temperature range 10.0–35.0 °C. The second and third systems were investigated at 35.0 °C and χ values vary from 0.15 to 0.32, and 0.11 to 0.19, respectively, as the polymer volume fraction varies from 0.32 to 0.12. The results have been applied to the available data for the cationic equilibrium polymerization of tetrahydrofuran in benzene and have been used for the computation of the free energy of polymerization, ΔG_1c. The need for a ternary interaction parameter of the type χ_msp for the ΔG_1c expression is discussed.