Extinction of diffusion flames adjacent to flat surfaces of burning polymers

Extinction of the diffusion flames in the stagnation‐point flow above the commercial polymers, poly(methyl methacrylate), polyoxymethylene (two types), polyethylene (three types), and polystyrene, is studied. The extinction data are used in a theory developed to obtain overall rate parameters for gas‐phase combustion of these fuels. Calculated overall rate parameters are corrected for surface heat loss by radiation. It is found that radiation corrections are most significant for polyethylene and polystyrene, in part because of their somewhat higher surface temperatures. Surface regression rates and corresponding surface temperatures are measured to aid in the radiation correction. The results are also used in an Arrhenius‐type rate expression to obtain overall activation energies for the thermal degradation of these polymers for comparison with the literature. Effects of surface losses on flame extinction are discussed.