Modeling the Influence of Diffusion-Controlled Reactions and Residual Termination and Deactivation on the Rate and Control of Bulk ATRP at High Conversions

摘要: In high-conversion atom transfer radical polymerization (ATRP), all the reactions, such as termination, deactivation, dormant chain activation, monomer propagation, etc. could become diffusion controlled sooner or later, depending on relative diffusivities of involved reacting species. These diffusion-controlled reactions directly affect rate and control polymer molecular weight. A model is developed to investigate influence high conversion ATRP kinetics. Model simulation reveals that termination slightly increases rate, but it deactivation causes auto-acceleration in (“gel effect”) loss control. At conversions, chains are “trapped” because However, centers can still migrate through (1) deactivation–activation cycles (2) which introduce “residual termination” reactions. It found does not have much The migration propagation however facilitate catalytic radicals, improves weight some extent. Dormant activation also finally stop when system approaches its glass state.