2203-12-5Relevant academic research and scientific papers
Thermolyse en solution de percarbonates de O-alkyle et O,O-t-butyle
Bourgeois, Marie-Josephe,Campagnole, Monique,Filliatre, Claude,Maillard, Bernard,Villenave, Jean-Jaques
, p. 111 - 115 (2007/10/02)
In the framework of our study of the synthesis and use of free radical initiators, we have prepared several O,O-tert-butyl peroxycarbonates corresponding to primary (methyl and ethyl), secondary (isopropyl) and tertiary (tert-butyl) alcohols.The simple one-pot procedure, which we have perfected, uses N,N'-cabonyldiimidazole as the starting reagent and either O,O-tert-butylimidazolyl percarboxylate or O-alkylimidazolyl carboxylate (in the case of the tertiary alcohol) as an intermediate.The yields of the preparation reactions are fairly good (65-70 percent).The chemical study, i.e. the analysis of the products, of the thermal decomposition in triisopropylbenzene of the prepared O-alkyl and O,O-tert-butyl peroxycarbonates has performed as well as the kinetic one: as for the latter we used Differential Scanning Microcalorimetry.We have observed that the reaction proceeds essentially via the homolysis of the peroxidic bond: no induced decomposition appears even for initial concentrations up to 1 M.The major products arise from reactions of the free radicals formed in the O-O-bond cleavage.The thermal stabilities of the various peroxycarbonates are similar and close to that of tert-butyl peroxybenzoate.Therefore, they are free radical initiators able to give tert-butoxy radicals at lower temperatures than the commonly used di-tert-butyl peroxide.
