1 research outputs found
Time-Resolved EPR as a Tool to Investigate Oxygen Quenching in Photoinitiated Radical Polymerizations
It
is challenging to obtain absolute rate constants for the quenching
of organic radicals by molecular oxygen because they often do not
present absorbance in the UV–vis range. Here, it is shown that
time-resolved EPR (chemically induced dynamic electron polarization,
or CIDEP) spectroscopy is useful in establishing rate constants for
the addition of benzoyl radicals to molecular oxygen. It was found
that benzoyl radicals are particularly reactive toward O<sub>2</sub> and can, therefore, act as oxygen scavengers in the initiating phase
of radical polymerizations. Kinetic simulations underpin this reactivity