Epoxy resins. III. Application of fourier transform IR to degradation studies of epoxy systems

Abstract

Abstract Three cured epoxy resins were investigated under various degradation conditions by Fourier transform infrared (FTIR) spectroscopy for measurement. The epoxy resins were the diglyadyl ethers of bisphenol A (DGEBA), phenolphthalein (DGEPP), and 9,9‐bis(4‐hydroxyphenyl)fluorene (DGEBF). The thermal stability order of functional groups that incurred DGEBA was total methyl group ∼ total benzene ring > methylene > p ‐phenylene > ether linkage > isopropylidene. The oxidative thermal and photodegradation processes were found to be related to the classical autocatalytical oxidation of aliphatic hydrocarbon segments. The Wieland rearrangement, Norrish‐type reaction, Claisen rearrangement, and other possible degradation mechanisms were suggested by the data.