Understanding dispersity control in photo‐ atom transfer radical polymerization: Effect of degree of polymerization and kinetic evaluation

In photo-atom transfer radical polymerization (ATRP), dispersity can be efficiently controlled by varying the deactivator concentration. this work, we provide mechanistic insight into dispersity-controlled photo-ATRP conducting detailed kinetics under a range of conditions. For lower polymers, conventional first-order kinetic profile was observed accompanied linear evolution number average molecular weight (Mn) with conversion while reactions reached moderate to high conversions (between 66% and 93%). Whereas, when polymers were targeted, Mn remained relatively constant throughout ceased at less than 50% conversion. particular, for Ð = 1.84, significant deviation between theoretical experimental weights evident. This unambiguously attributed slow initiation as indicated 1H NMR, where percentages unreacted initiator observed. Importantly, addition ligand plateau re-initiated led complete consumption initiator, thus enabling synthesis one-pot diblock copolymers. We subsequently evaluated effect degree (DP) on obtained catalyst ratio maintained. Based interpolation those experiments results, could predict conditions any desirable DPs dispersities.