1,5-HYDROGEN TRANSFER - A HITHERTO IGNORED DECAY CHANNEL IN THE PHOTODEGRADATION OF POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE)

We present the results of a theoretical study and pur forward a novel mechanism for the photodegradation of the polymer poly (2,6-dimethyl-1 ,4-phenylene oxide) (PPE). The primary step is a 1,5-hydrogen transfer from the methyl group of one ring system to the ipso-carbon of the ad jacent monomeric unit. Therefore, in contrast to other proposed mechan isms, the primary step is a result of the three-dimensional structure of PPE rather than a consequence of structural defects in the polymer chain or of impurities.