Photodegradation of polyimides. I. A spectral, viscometric, chromatographic, and weight loss investigation of polyimides based on a hexafluorinated dianhydride

Abstract

Abstract The photodegradation of aromatic‐dianhydride‐based polyimide films in air with hexafluorinated groups in the dianhydride moiety is characterized by significant weight loss and chain cleavage. A conventional polyimide film based on pyromellitic dianhydride yields little decomposition under similar conditions of photolysis. Emission changes on photolysis of polyimide solutions demonstrate an efficient rearrangement to yield a highly fluorescent species which can be used as an effective tool for following the degradation process.