Kinetics of Stable Free Radical Mediated Polymerization inside Submicron Particles

Controlled/living radical polymerization systems in which the active period is extremely small, ϕ A  ≪ 1, such as the cases of stable free radical mediated polymerization (or nitroxide mediated polymerization) and atom transfer radical polymerization, are considered theoretically. The polymerization rate, R p , for such systems increases by lowering the trapping agent concentration [ X ]. When the polymerization is conducted inside small particles, R p decreases with D   p 3below the diameter D p,SMC at which a single molecule concentration (SMC) is equal to [ X ] bulk . On the other hand, when the average number of trapping agents in a particle $\bar n_X$ is smaller than about 10, the fluctuation of n X among particles is significant, which leads to a larger R p than in the cases where all particles contain the same n X . Because of the effects of SMC and fluctuation, R p may show an acceleration window, D p,SMC  <  D p  <  D p,Fluct where R p is slightly larger than that in bulk.