Persistent Link:
http://hdl.handle.net/10150/184988
Title:
New aspects of tetramethylene initiation in polymer chemistry.
Author:
Clever, Hester Ann.
Issue Date:
1990
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:
Hall's Bond Forming Initiation Theory, derived for [2 + 2] systems, was applied to [4 + 2] systems. Polymerizable electron-rich and electron-poor olefins were reacted to obtain evidence for reactive intermediates using polymerization as a trap. A diradical intermediate was successfully trapped in reactions of 1-methoxy-1,3-butadiene with methyl 2,2-dicyanoacrylate, dimethyl cyanofumarate, trimethyl ethylenetricarboxylate, maleic anhydride and acrylonitrile. Diradical intermediates were also trapped in reactions of isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, cis and trans-piperylene and 2,5-dimethyl-2,4-hexadiene with acrylonitrile. Copolymers were obtained in all cases. Copolymerization was accompanied by [4 + 2] cycloaddition. A zwitterionic intermediate was successfully trapped in the reactions of p-anisyl-1,3-butadiene and 1-phenyl-1,3-butadiene with various leaving groups in the β-position. Homopolymer of the arylbutadiene was obtained in all cases. Polymerization was initiated from a cationic species which arose from the elimination of the leaving group from a zwitterionic hexamethylene species. Polymerization was accompanied by [4 + 2] cycloaddition. Reactions of p-anisyl-1,3-butadiene and 1-phenyl-1,3-butadiene with methyl 2,2-dicyanoacrylate, dimethyl cyanofumarate, trimethyl ethylenetricarboxylate gave only the [4 + 2] cycloadduct. No polymer was formed in this reaction and no evidence for a reactive intermediate was obtained. The BFI theory was also applied to Group Transfer Polymerization reactions to determine whether the reaction mechanism involved a tetramethylene diradical intermediate. No styrene was incorporated into the methyl acrylate polymer, and so no evidence for a radical intermediate was obtained. LUMO energies calculated by AM1 were compared to reduction potential and UV data for tetrasubstituted and trisubstituted electrophilic olefins. The trends exhibited by the calculated LUMO energies agreed well with the experimental data, implying that calculations may be a reasonable method of predicting reactivity.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Hall, H. K, Jr.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleNew aspects of tetramethylene initiation in polymer chemistry.en_US
dc.creatorClever, Hester Ann.en_US
dc.contributor.authorClever, Hester Ann.en_US
dc.date.issued1990en_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.abstractHall's Bond Forming Initiation Theory, derived for [2 + 2] systems, was applied to [4 + 2] systems. Polymerizable electron-rich and electron-poor olefins were reacted to obtain evidence for reactive intermediates using polymerization as a trap. A diradical intermediate was successfully trapped in reactions of 1-methoxy-1,3-butadiene with methyl 2,2-dicyanoacrylate, dimethyl cyanofumarate, trimethyl ethylenetricarboxylate, maleic anhydride and acrylonitrile. Diradical intermediates were also trapped in reactions of isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, cis and trans-piperylene and 2,5-dimethyl-2,4-hexadiene with acrylonitrile. Copolymers were obtained in all cases. Copolymerization was accompanied by [4 + 2] cycloaddition. A zwitterionic intermediate was successfully trapped in the reactions of p-anisyl-1,3-butadiene and 1-phenyl-1,3-butadiene with various leaving groups in the β-position. Homopolymer of the arylbutadiene was obtained in all cases. Polymerization was initiated from a cationic species which arose from the elimination of the leaving group from a zwitterionic hexamethylene species. Polymerization was accompanied by [4 + 2] cycloaddition. Reactions of p-anisyl-1,3-butadiene and 1-phenyl-1,3-butadiene with methyl 2,2-dicyanoacrylate, dimethyl cyanofumarate, trimethyl ethylenetricarboxylate gave only the [4 + 2] cycloadduct. No polymer was formed in this reaction and no evidence for a reactive intermediate was obtained. The BFI theory was also applied to Group Transfer Polymerization reactions to determine whether the reaction mechanism involved a tetramethylene diradical intermediate. No styrene was incorporated into the methyl acrylate polymer, and so no evidence for a radical intermediate was obtained. LUMO energies calculated by AM1 were compared to reduction potential and UV data for tetrasubstituted and trisubstituted electrophilic olefins. The trends exhibited by the calculated LUMO energies agreed well with the experimental data, implying that calculations may be a reasonable method of predicting reactivity.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistryen_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.contributor.advisorHall, H. K, Jr.en_US
dc.identifier.proquest9024500en_US
dc.identifier.oclc706828264en_US
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