| Abstract: | A novel driven-rod, radiant pyrolysis technique has been used to study the steady-state linear regression of vertically mounted poly(methyl methacrylate) and polypropylene rods degrading from the top under high-flux, nonflaming conditions that simulate those of combustion. With this technique reliable temperature-depth and oxygen-depth profiles have been obtained and used to calculate the observed mass loss rates and to elucidate the mode of polymer degradation during combustion, respectively. For poly(methyl methacrylate) burning in this rod configuration, condensed phase oxidation is unimportant and the degradation mechanism is similar to that under more conventional slow-heating conditions in the absence of air. In contrast, for burning polypropylene condensed phase oxidation occurs; the lack of oxygen incorporation suggests that the polymer degrades by oxygen-promoted pyrolysis. |
