The thermal decomposition of diaroyl peroxides in some solvents

Coleman, Michael William

(1972)

Coleman, Michael William (1972) The thermal decomposition of diaroyl peroxides in some solvents.

Our Full Text Deposits

Full text access: Open

10098200.pdf - 25.15 MB

Abstract

The mechanism of the thermal decomposition of perfluorobenzoyl peroxide in benzene has been investigated in a study of the reaction kinetics and product distributions for a series of initial peroxide concentrations. The initial thermal dissociation of the peroxide is superimposed on a 1.5-order induced decomposition at low and on a first-order induceddecomposition at higher [P]o. The pentafluorobenzoyloxy radicals which are formed from the initial homolysis either attack the solvent or decarboxylate to pentafluorophenyl radicals which also attack the solvent, both processes forming a-complexes. These a-complexes are responsible for induced decomposition in chain propagation reactions. At low [P] chain termination occurs through dimerisation ofsimilar a-complexes; at higher CPQ chain termination occurs by reaction of pentafluorobenzoyloxy radicals with a-complexes. The thermal decomposition of perfluorobenzoyl peroxide in chlorobenzene and broraobenzene was investigated. Stabilisation of pentafluorobenzoyloxy radicals in these solvents produces high stationary concentrations of the corresponding a-complexes. The first-order thermal dissociation of the peroxide is superimposed on a first-order induced decomposition over the whole [P] range in both solvents.e-complexes are responsible for the induced decomposition, and chain termination occurs primarily through halogen abstraction from a-complexes by pentafluorobenzoyloxy radicals. The perfluorobenzoyl peroxide-fluorobenzene reaction has also been studied. Investigation of the benzoyl peroxide-hexafluorobenzene reaction shows the initial first-order homolysis occurring concurrently with a 1.5-order induced decomposition. Phenylation of hexafluorobenzene forms a-complexes which are responsible for the slow induced decomposition. Chain termination occurs mainly by dimerisation of a-complexes producing a high-boiling residue. Thermal decomposition of diaroyl peroxides in several perfluoroalicyclic solvents was studied with the aim of finding a group of solvents which are insert to free-radical attack. Reaction products were found to be derived solely from the peroxides so that radical interaction with the solvents appears unlikely.

Information about this Version

This is a Accepted version
This version's date is: 1972
This item is not peer reviewed

Link to this Version

https://repository.royalholloway.ac.uk/items/7ae01d61-7108-478e-8906-c15ea1899c4f/1/

Item TypeThesis (Doctoral)
TitleThe thermal decomposition of diaroyl peroxides in some solvents
AuthorsColeman, Michael William
Uncontrolled KeywordsChemical Engineering; Applied Sciences; Decomposition; Diaroyl; Perfluorobenzoyl Peroxide; Peroxides; Perfluorobenzoyl Peroxide; Solvents; Some; Thermal
Departments

Identifiers

ISBN978-1-339-62263-7

Deposited by () on 31-Jan-2017 in Royal Holloway Research Online.Last modified on 31-Jan-2017

Notes

Digitised in partnership with ProQuest, 2015-2016. Institution: University of London, Bedford College (United Kingdom).


Details