EPOXY-RESIN ANALYSIS BY FOURIER-TRANSFORM MASS-SPECTROMETRY - A COMPARISON OF PYROLYSIS AND LASER ABLATION

The pyrolysis or decomposition products of cured, fire retardant epoxy resin (diglycidyl ether of tetrabrominated bisphenol A) were compared under several different conditions: thermal pyrolysis, laser ablation and cw laser pyrolysis. Volatile neutral products were ionized by electron impact, except in the case of direct laser ionization, and detected by Fourier transform mass spectrometry. Pyrolysis gave high molecular weight fragments and a considerable amount of information about the monomer composition. Detection of directly ionized, laser-ablated products gave some molecular fragments from microprobe sample sizes, although the spectra are complex. Laser ablation/electron impact ionization produced mostly low molecular weight fragments that gave limited information about the material. Laser pyrolysis using a cw argon ion laser provided some large fragments and consumed small amounts of sample. The relationships and analytical value of these techniques are discussed.