COMPOSITIONAL ANALYSIS OF EPOXY MATRICES OF CARBON-FIBER COMPOSITES BY PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY

The combination of gas chromatography with mass spectrometry or high-resolution mass spectrometry permitted the identification of a number of components in the matrices of carbon-fibre composites. Analysis of the composite Fibredux 913 C, cured at 120-degrees-C, by this method permitted identification of epoxy resin N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl-methane (TGDDM), diglycidylether of bisphenol A type resin and accelerator 3-(3,4-dichlorophenyl)-1,1-dimethylurea, and, in the matrix of the Fibredux 914 C composite, cured at 175-degrees-C, TGDDM and a polysulphone, probably of the poly(arylether) type. The matrix of this composite contains a further component that releases aminophenols. These components yield sufficient amounts of pyrolysis products to make possible the use of pyrolysis gas chromatography in the quality control of these composites. However, the absence of characteristic pyrolysis products of hardeners prevents their unambiguous identification by this method.