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

The fast transient fluorescence technique was used to study the sol-gel pha se transition in free-radical crosslinking copolymerization of methyl metha crylate (MMA) and ethylene glycol dimethacrylate. Pyrene (Py) was used as a fluorescence probe for the in situ polymerization experiments. Fluorescenc e lifetimes of Py from its decay traces were measured and used to monitor t he gelation process. Stern-Volmer kinetics was employed to determine the qu enching rate constant before the onset of gelation. The MMA consumption rat e was measured during the gelation process using the Stern-Volmer model. (C ) 2000 Elsevier Science Ltd. Ail rights reserved.