Equilibrium anionic polymerization of α‐methylstyrene in p‐dioxane

The equilibrium anionic polymerization of α‐methylstyrene in p ‐dioxane, with potassium as initiator, has been investigated at 5, 15, 25, and 40°C by using high‐vacuum techniques. The comparison of these results with those obtained previously for the equilibrium polymerization of α‐methylstyrene in tetrahydrofuran revealed that, although the values of Δ G 1c , the free‐energy change upon the polymerization of 1 mole of liquid monomer to 1 bases‐mole of liquid amorphous polymer of infinite chain length, are the same for both systems, there is a distinct effect of the solvent. This effect is reflected in the value of monomer equilibrium concentration and its variation with polymer concentration and is explained in terms of a solvent–monomer and solvent–polymer interaction parameter.