The thermal degradation in air of poly(ethylene) glycol, poly(vinyl alcohol), and a combination of the two polymers in alumina-containing additives has been studied by gas chromatography/mass spectrometry, thermal analysis, and CP-MAS C-13 NMR. Both polymers in alumina degraded as previously described for the pure polymers, For the polymer mixture, both polymers degraded independently of each other. Thermal analysis of the various samples showed that the additive, sodium lignosulfonate, required the highest temperature for burnout. Product analysis of the pure and combined polymers along with the respective decomposition mechanisms are summarized.