Autoxidative Degradation of Poly(phenylacetylene)

Autooxidative degradation of high molecular-weight poly(phenylacetylene) (PPhA) in solid state and in solution was studied using the size exclusion chromatography (SEC) and UV, IR, and EPR spectrometry. No degradation was observed on PPhA stored in vacuum, whereas the polymer exposed to air was found to degrade without any induction period. No evidence of a cross-linking of oxidized PPhA was observed. The degradation of PPhA was found to be: (i) practically non-influenced by an ambient, diffuse day-light; (ii) of the random type (i.e. each main-chain bond of PPhA has the same probability of being ruptured); and (iii) fast enough to influence the results of SEC measurements.