Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
The anionic polymerization of three monomers, 2-isopropenyl-4,5-dimethyloxazole(I), 2-isopropenylthiazole(II), and 2-isopropenylpyridine(III), was studied in THF. These monomers produced red-colored living polymers on addition of sodium naphthalene or living α-methylstyrene tetramer as an initiator. It was observed that a considerable amount of monomer remained in the respective living polymer-monomer system, indicating that an equilibrium between the polymer and the monomer existed as in the case of α-methylstyrene. At lower temperatures, the conversion of the monomer to the polymer increased. The equilibrium monomer concentrations [Me] were determined at different temperatures, and the heats (ΔH) and the entropies (ΔS°) of polymerization were obtained by plotting In(1/[Me]) against 1/T as ΔH = -9.4, -6.8, and -6.2 kcal/mole, ΔS°S = -22.9, -16.5, and -16.6, eu for I, II, and III, respectively.
Type of Medium: