Abstract
The photoreaction of peroxy radicals of polytetrafluoroethylene (PTEE) was investigated by means of the molecular orbital (intermediate neglect of differential overlap/spectroscopy-configuration interaction (INDO/S-CI)) calculations of the excited states of model compounds for two types of radicals, i.e. the endchain peroxy and midchain peroxy radicals. Calculations showed that the midchain redicals are exited to the second lowest excited doublet (D2) state, which is responsible for the photoreaction, with much higher efficiency than the endchain peroxy radicals. The bond order perturbations accompanied by the transition from the ground doublet (D0) state to the D2 state in the midchain radicals seem to well explain the experimental results.