Thermal degradation of new and aged urethane foam and epon 826 epoxy.

Thermal desorption spectroscopy was used to monitor the decomposition as a function of temperature for the foam and epoxy as a function of temperature in the range of 60 C to 170 C. Samples were studied with one day holds at each of the studied temperatures. Both new (FoamN and EpoxyN) and aged (FoamP and EpoxyP) samples were studied. During these ~10 day experiments, the foam samples lost 11 to 13% of their weight and the EpoxyN lost 10% of its weight. The amount of weight lost was difficult to quantify for EpoxyP because of its inert filler. The onset of the appearance of organic degradation products from FoamP began at 110 C. Similar products did not appear until 120 C for FoamN, suggesting some effect of the previous decades of storage for FoamP. In the case of the epoxies, the corresponding temperatures were 120 C for EpoxyP and 110 C for EpoxyN. Suggestions for why the aged epoxy seems more stable than newer sample include the possibility of incomplete curing or differences in composition. Recommendation to limit use temperature to 90-100 C for both epoxy and foam.