Termination of Surface Radicals and Kinetic Analysis of Surface‐Initiated RAFT Polymerization on Flat Surfaces

Abstract si‐RAFT polymerization is widely used for surface modification. However, how the surface radicals terminate requires further elucidation. A kinetic model is developed for si‐RAFT via the R group approach. The model describes the molecular weight of grafted polymers as well as polymer layer thickness and various chain concentrations. It is shown that surface/surface radical termination plays an important role. The termination is facilitated by the migration of surface radicals through “hopping” and “rolling” mechanisms. “Hopping” occurs through activation/deactivation cycles between surface and solution chains, dependent on the RAFT concentration in solution. “Rolling” occurs through transfers between surface/surface chains, dependent on the grafting density at surface. magnified image