Products from the thermal decomposition of four polyurethane foams heated to temperatures in the range 220 to 400 °C, in atmospheres of nitrogen, of 6% oxygen in nitrogen and of air were examined for some of the anticipated toxic materials. When phosphorus‐containing inhibitors were added to or chemically incorporated in the foams, phosphorus compounds were evolved under most of the conditions employed. Other materials detected were hydrogen cyanide, isocyanate, urea, halogenated compounds and alkenes. A brief discussion is given of the hazard presented by polyurethane foams decomposing under these conditions.
The thermal decomposition of methane has been studied in a chemical shock tube at pressuresup to 20atm over a temperature range ofbetween 1750 and 2700 K and for reaction times up to 2.5 ms. Attention is drawn to some of the experimental features of the shock tube and to the fact that reaction temperatures were measured.Optimum conditions for the production of acetylene from methane are suggested, and the relatively small effect of pressure on the acetylene yields is noted.Values for activation energy (93.6 kcal/mol) and frequency factor (3.8 x lOI3 s-' for methane decomposition are given. The experimental results obtained are discussed in connection with suggested mechanisms of decomposition. In the discussion attention is drawn to the difficulty of predicting acetylene yields arising from the incomplete understanding of the mechanism of acetylene decomposition and of "carbon" formation under the conditions employed.
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