Autoxidative degradation of high molecular-weight poly(phenylacetylene
) (PPhA) in the solid state and in solution was studied using the size
exclusion chromatography (SEC) and UV, IR, and EPR spectrometry. No d
egradation was observed on PPhA stored in vacuum, whereas the polymer
exposed to air was found to degrade without any induction period. No e
vidence of a cross-linking of oxidized PPhA was observed. The degradat
ion of PPhA was found to be: (i) practically non-influenced by an ambi
ent, 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) fa
st enough to influence the results of SEC measurements.