Polymer reactions. III. Structure of polypropylene hydroperoxide

Oxidation of polypropylene introduces hydroperoxide groups into the polymer. Infrared spectroscopy has determined that more than 90% of these groups are intramolecularly hydrogen bonded. The sequential lengths and sequence distributions of these neighboring hydroperoxides were estimated from the electronic spectra of the polyenes derived from the polypropylene hydroperoxide by two methods: (1) reduction, acetylation, and pyrolysis, and (2) reduction and dehydration. The results indicate that all the hydroperoxide groups are present in sequences of length two and greater. Intramolecular hydrogen abstraction during oxidation could account for the formation of these neighboring hydroperoxides.