Title

Photodegradation of Polyimides .4. Mechanism for the Photooxidation Process Based on a Model-Compound

Document Type

Article

Publication Date

1992

Department

Chemistry and Biochemistry

Abstract

Based on analysis of the photochemistry of a model compound, N-phenylphthalimide, the photolysis of a polyimide derived from 4,4'-oxydianiline (ODA) and a diarylanhydride with a hexafluorinated isopropylidine bridging group (6F) is proposed to proceed via formation of a phthalic anhydride type photoproduct. The quantum yield for product formation of N-phenylphthalimide is quite low ( < 10(-3)) indicating a rather inefficient first step in the overall oxidative degradation process. However, based on the efficiency of the photo-oxidation of the primary photoproducts, a process leading to the ultimate failure and complete ablation of the 6F-ODA films in air upon exposure to the unfiltered output of a mercury lamp is postulated.

Publication Title

Polymer

Volume

33

Issue

15

First Page

3162

Last Page

3168