Chemiluminescence from the thermal oxidation of polyisoprene and polybutadiene I. Influence of oxygen pressure on the chemiluminescence of polyisoprene during its oxidation

The influence of oxygen pressure p (0.016-0.1 MPa) on polyisoprene thermal oxidation at 100 °C has been studied by chemiluminescence (CL). The maximum CL intensity was found to be almost proportional to p, whereas the induction time is influenced in the same way but to a lesser extent. Assuming that the classical mechanistic scheme with initiation by bimolecular hydroperoxide decomposition and termination by bimolecular radical combination, partially studied by Tobolsky and co-workers in the 1950s, is valid, it was established that chemiluminescence originates essentially from hydroperoxide decomposition. A theory which tries to reconcile this result with the most popular hypothesis according to which light is emitted by terminating peroxyl bimolecular combination is proposed.