PHOTO-INDUCED RADICAL COPOLYMERIZATIONS OF ELECTRON-RICH OLEFINS WITH ELECTRON-POOR OLEFINS.

Persistent Link:
http://hdl.handle.net/10150/184135
Title:
PHOTO-INDUCED RADICAL COPOLYMERIZATIONS OF ELECTRON-RICH OLEFINS WITH ELECTRON-POOR OLEFINS.
Author:
LEE, CHERYLYN.
Issue Date:
1987
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This study is a systematic investigation of the parameters and conditions necessary for photo-induced radical copolymerizations of donor olefins with acceptor olefins in the absence of an initiator. Very few cases have been previously reported and no mechanistic details of the initiation have been proposed in the literature. Our results show that the photoinitiation depends on the relative donor and acceptor strengths of the monomers, as well as the solvent. The highest occupied molecular orbital (HOMO) of the donor and the lowest unoccupied molecular orbital (LUMO) of the acceptor must be at the appropriate energy levels in order to produce a radical initiating species upon photoexcitation of the electron donor-acceptor (EDA) complex. If the donor-acceptor interaction is too weak, no copolymerization occurs. The excited complex (contact ion pair) presumably decays back to the ground state faster than producing an initiating species. If the donor-acceptor interaction is too strong, the excited complex dissociates to the free ions which could initiate ionic homopolymerization rather than radical copolymerization. The solvent may also determine the course of the reaction. In two cases, copolymerizations, which could be photo-induced in 1,2-dichloroethane, could not be photo-induced in acetonitrile. Dissociation of the excited complex (contact ion pair) is favored in polar solvents, such as acetonitrile, which are able to stabilize the ion radicals. This initiation method produces high molecular weight copolymers that may be cast into transparent films.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Polymers.; Polymerization.; Alkenes.; Electron donor-acceptor complexes.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titlePHOTO-INDUCED RADICAL COPOLYMERIZATIONS OF ELECTRON-RICH OLEFINS WITH ELECTRON-POOR OLEFINS.en_US
dc.creatorLEE, CHERYLYN.en_US
dc.contributor.authorLEE, CHERYLYN.en_US
dc.date.issued1987en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis study is a systematic investigation of the parameters and conditions necessary for photo-induced radical copolymerizations of donor olefins with acceptor olefins in the absence of an initiator. Very few cases have been previously reported and no mechanistic details of the initiation have been proposed in the literature. Our results show that the photoinitiation depends on the relative donor and acceptor strengths of the monomers, as well as the solvent. The highest occupied molecular orbital (HOMO) of the donor and the lowest unoccupied molecular orbital (LUMO) of the acceptor must be at the appropriate energy levels in order to produce a radical initiating species upon photoexcitation of the electron donor-acceptor (EDA) complex. If the donor-acceptor interaction is too weak, no copolymerization occurs. The excited complex (contact ion pair) presumably decays back to the ground state faster than producing an initiating species. If the donor-acceptor interaction is too strong, the excited complex dissociates to the free ions which could initiate ionic homopolymerization rather than radical copolymerization. The solvent may also determine the course of the reaction. In two cases, copolymerizations, which could be photo-induced in 1,2-dichloroethane, could not be photo-induced in acetonitrile. Dissociation of the excited complex (contact ion pair) is favored in polar solvents, such as acetonitrile, which are able to stabilize the ion radicals. This initiation method produces high molecular weight copolymers that may be cast into transparent films.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectPolymers.en_US
dc.subjectPolymerization.en_US
dc.subjectAlkenes.en_US
dc.subjectElectron donor-acceptor complexes.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.identifier.proquest8716355en_US
dc.identifier.oclc698707762en_US
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