Analysis of degradation products on epoxy surfaces subjected to pulse and glow type discharges

The degradation of epoxy specimens, exposed to pulse type and pulseless glow discharges, was investigated. Epoxy coverered, plane- parallel electrodes were employed; the mean discharge magnitude of the pulse type discharges was measured as a function of exposure time. The glow discharge light intensity was monitored as a function of time using a photomultiplier tube (PMT). Preliminary results indicate erratically changing magnitude of both the pulse type discharge and the photoemission prior to the disappearance of the pulses, at which point the PMT output is observed to assume a relatively constant value. The latter result infers a quasi constant glow discharge intensity for long exposure times. The change in the discharge behavior is ascribed to the chemical reactions occurring in the vapor phase and on the epoxy specimen surface. The surface deposition products are analyzed using ESCA, Debye-Scherrer X-ray diffraction and Ion Chromatography measurement techniques.