Insights into Oxidation Pathways, from Gaseous Products of Polypropylene with Selective Isotopic Labeling

Polymer degradation mechanisms are exceedingly complex, but their understanding is fundamental to improving material durability. We have initiated selective isotopic labeling as a means of tracking oxidation chemistry, and chose polypropylene (PP) to test this approach, since it has a simple structure (three unique carbon sites along the chain), and is of commercial importance. There has in fact been much interest in the stability of PP, and many prior studies have contributed to the ongoing development of understanding its degradation processes. In recent work, we applied ^(13)C NMR to examine the solid-phase oxidation products of isotopically labeled PP; in this Communication, we begin identifying the volatile products.