The Effect of Bulky Ester Alkyl Substituents on Rate Constants of Radical Polymerization of Dialkyl Fumarates

摘要

The radical polymerization of dialkyl fumarates bearing various ester alkyl groups was investigated to evaluate the propagation and termination rate constants (k_p and k_t) by means of electron spin resonance spectroscopy. It was revealed that the introduction of tert-butyl ester group promoted the polymerization reactivity not only the retardation of the termination, but also by the acceleration of the propagation despite of steric repulsion by the bulky substituents. The latter was interpreted by the stereospecific propagation leading to the diisotactic polymer formation.