The pyrolysis of acetylene‐styrene mixtures between 450 and 550°C

The pyrolysis of acetylene‐styrene mixtures has been studied from 450–550°C in a quartz reaction vessel in the absence and presence of O 2 or NO. The rates of disappearance of reactants and formation of adducts are first‐order in each reactant. The major product is polymer, with the adducts accounting for about 2.5% and 6.2% of the styrene removed at 450 and 550°C, respectively. The acetylene‐to‐styrene removal ratio is about 27 independent of temperature. The adducts formed are methyl indene and 1,2‐dihydronaphthalene. These are about half‐suppressed in the presence of O 2 or NO. The rate coefficients for reactant removal and adduct formation are:\documentclass{article}\pagestyle{empty}\begin{document}$$ \log \{ k\{ {\rm C}_{\rm 2} {\rm H}_{\rm 2} \},M^{ - 1} {\rm s}^{ - 1} \} = 7.53 \pm 0.10 - (90.6 \pm 1.5)/2.3RT $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ \log \{ k\{ {\rm C}_{\rm 8} {\rm H}_{\rm 8} \},M^{ - 1} {\rm s}^{ - 1} \} = 6.63 \pm 0.60 - (98.5 \pm 8.8)/2.3{\rm }\,RT $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ \log \{ k\{ {\rm C}_{{\rm 10}} {\rm H}_{{\rm 10}} \},M^{ - 1} {\rm s}^{ - 1} \} = 8.27 \pm 0.66 - (143.3 \pm 9.8)/2.3RT $$\end{document}where the activation energies are in kJ/mol and the uncertainties are one standard deviation. As the reaction proceeds, the methyl indene and 1,2‐dihydronaphthalene decompose, and indene and naphthalene are formed. In addition, an unidentified isomer of naphthalene is produced as an initial minor product, and it also decomposes as the reaction proceeds.