Reaction of hydroperoxy t-butyl radicals and t-butyl peroxy t-butyl radicals in relation to chain propagation in combustion
- Univ. of Aberdeen (United Kingdom). Dept. of Chemistry
- Ministry of Defence, Chaklala Rawaepindi (Pakistan). Desto Labs.
- Univ. of Southern California, Los Angeles, CA (United States). Loker Hydrocarbon Research Inst.
Hydroperoxyl t-butyl radicals or t-butyl peroxy t-butyl radicals were generated in an oxygen-free system. This allowed an unequivocal measure of the ratio of olefin to epoxide formation to be made. For hydroperoxy alkyl radicals, the two paths are competitive over the temperature range 413--473 K with olefin production becoming more dominant as the temperature is raised. Some controversy surrounds the primary mechanism for the oxidation of alkyl radicals at temperatures up to 900 K. Strong arguments have been put forward for both exclusive olefin and exclusive epoxide formation. By comparing their results with this work, the authors conclude that the primary path is indeed exclusive olefin formation. The controversy may be reconciled by proposing that epoxide formation arises as the result of secondary reactions involving the addition of HO{sub 2} or RO{sub 2} to the primary olefin production. Pressure-dependent processes complicate the issue. However, it is difficult to see how any collisional stabilization process would lead to increased epoxide formation in view of the present evidence available. This work shows that the addition of RO{sub 2} to olefins results in the almost exclusive production of epoxide, at least at lower temperatures. For t-butyl peroxy t-butyl radicals over the temperature range 363-403 K, the path involving the production of epoxide is {>=}98%. Further evidence is required on the reaction of hydroperoxy and alkylperoxy alkyl radicals.
- OSTI ID:
- 93227
- Report Number(s):
- CONF-940711--
- Country of Publication:
- United States
- Language:
- English
Similar Records
The addition of molecular oxygen to hydroperoxy-propyl radicals
Systematic exploration of the thermochemistry for a set of peroxy hydroperoxy-alkyl radicals