Cross polarization and magic angle spinning C-13 nuclear magnetic resonance spectroscopy (CP-MAS C-13 NMR) has been used to investigate the thermal degradation of poly(ethylene glycol) (PEG)-alumina, poly(vinyl alcohol) (PVA)-alumina, and a mixture of 6% PEG and 0.5% PVA in alumina. Samples were prepared by thermally treating each polymer at 450 degrees C to remove pre-specified weight losses. The results showed that the polymer chains of both PEG a nd PVA thermally degraded as postulated in previously published mechanistic studies based on volatile degradation product analyses. The CP-MAS C-13 NMR spectra of PEG and PVA in alumina showed that the two polymers thermally decomposed independently of each other.