Fast transient fluorescence technique for monitoring gelation in free-radical crosslinking copolymerization

The fast transient fluorescence technique was used to study the sol–gel phase transition in free-radical crosslinking copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate. Pyrene (Py) was used as a fluorescence probe for the in situ polymerization experiments. Fluorescence lifetimes of Py from its decay traces were measured and used to monitor the gelation process. Stern–Volmer kinetics was employed to determine the quenching rate constant before the onset of gelation. The MMA consumption rate was measured during the gelation process using the Stern–Volmer model.