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Living polymerization for the introd...

Elkins, Casey Lynn.

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Living polymerization for the introduction of tailored hydrogen bonding.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Living polymerization for the introduction of tailored hydrogen bonding./
Author:	Elkins, Casey Lynn.
Description:	311 p.
Notes:	Source: Dissertation Abstracts International, Volume: 66-05, Section: B, page: 2608.
Contained By:	Dissertation Abstracts International66-05B.
Subject:	Chemistry, Polymer. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3177332
ISBN:	0542165406

Living polymerization for the introduction of tailored hydrogen bonding.
Elkins, Casey Lynn.

Living polymerization for the introduction of tailored hydrogen bonding. - 311 p.

Source: Dissertation Abstracts International, Volume: 66-05, Section: B, page: 2608.

Thesis (Ph.D.)--Virginia Polytechnic Institute and State University, 2005.

In an effort to synthesize macromolecules comprising both covalent and non-covalent bonding to tune ultimate physical properties, a variety of methodologies and functionalization strategies were employed. First, protected functional initiation, namely 3-[(N-benzyl-N-methyl)amino]-1-propyllithium and 3-(t-butyldimethylsilyloxy)-1-propyllithium, in living anionic polymerization of isoprene was used to yield well-defined chain end functional macromolecules. Using both initiating systems, polymers with good molar mass control and narrow molar mass distributions were obtained and well-defined chain end functionality was observed. There was no observed effect on the polymer microstructure from the polar functionality in the initiator, with &sim;92% 1,4- and 8% 3,4-enchainment observed in each case. Further investigation of the 3-[(N-benzyl-N-methyl)amino]-1-propyllithium initiated polyisoprenes proved that facile deprotection was not possible and residual catalyst was not removable from the polymer. However, polymers initiated with 3-(t-butyldimethylsilyloxy)-1-propyllithium were quantitatively hydrogenated and deprotected under relatively mild conditions to yield hydroxyl functional macromolecules in several architectures, including linear and star-shaped. Excellent conversion from arm polymer to star polymer was observed and well-defined macromolecules were obtained. Subsequently, a series of non-functional, hydroxyl functional, and 2-ureido-4[1H]-pyrimidone (UPy) chain end functional linear and star-shaped poly(ethylene-co-propylene)s were synthesized and characterized. The melt phase properties were investigated using melt rheology and the effect of macromolecular topology and multiple hydrogen bond functionality was investigated. Linear UPy functional poly(ethylene- co-propylene)s exhibited increased viscosity and shear thinning onset at lower frequencies than non-functional polymers of similar molar mass due to interaction of the multiple hydrogen bonding groups. Star-shaped UPy functional poly(ethylene-co-propylene)s showed inhibition to terminal flow and the absence of a zero shear viscosity in melt rheological characterization, indicative of a network like structure imparted from the multiple hydrogen bonding interactions.

ISBN: 0542165406Subjects--Topical Terms:

1018428
Chemistry, Polymer.

Living polymerization for the introduction of tailored hydrogen bonding.
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035 $a (UnM)AAI3177332
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100 1 $a Elkins, Casey Lynn. $3 1904844
245 1 0 $a Living polymerization for the introduction of tailored hydrogen bonding.
300 $a 311 p.
500 $a Source: Dissertation Abstracts International, Volume: 66-05, Section: B, page: 2608.
500 $a Chair: Timothy E. Long.
502 $a Thesis (Ph.D.)--Virginia Polytechnic Institute and State University, 2005.
520 $a In an effort to synthesize macromolecules comprising both covalent and non-covalent bonding to tune ultimate physical properties, a variety of methodologies and functionalization strategies were employed. First, protected functional initiation, namely 3-[(N-benzyl-N-methyl)amino]-1-propyllithium and 3-(t-butyldimethylsilyloxy)-1-propyllithium, in living anionic polymerization of isoprene was used to yield well-defined chain end functional macromolecules. Using both initiating systems, polymers with good molar mass control and narrow molar mass distributions were obtained and well-defined chain end functionality was observed. There was no observed effect on the polymer microstructure from the polar functionality in the initiator, with &sim;92% 1,4- and 8% 3,4-enchainment observed in each case. Further investigation of the 3-[(N-benzyl-N-methyl)amino]-1-propyllithium initiated polyisoprenes proved that facile deprotection was not possible and residual catalyst was not removable from the polymer. However, polymers initiated with 3-(t-butyldimethylsilyloxy)-1-propyllithium were quantitatively hydrogenated and deprotected under relatively mild conditions to yield hydroxyl functional macromolecules in several architectures, including linear and star-shaped. Excellent conversion from arm polymer to star polymer was observed and well-defined macromolecules were obtained. Subsequently, a series of non-functional, hydroxyl functional, and 2-ureido-4[1H]-pyrimidone (UPy) chain end functional linear and star-shaped poly(ethylene-co-propylene)s were synthesized and characterized. The melt phase properties were investigated using melt rheology and the effect of macromolecular topology and multiple hydrogen bond functionality was investigated. Linear UPy functional poly(ethylene- co-propylene)s exhibited increased viscosity and shear thinning onset at lower frequencies than non-functional polymers of similar molar mass due to interaction of the multiple hydrogen bonding groups. Star-shaped UPy functional poly(ethylene-co-propylene)s showed inhibition to terminal flow and the absence of a zero shear viscosity in melt rheological characterization, indicative of a network like structure imparted from the multiple hydrogen bonding interactions.
520 $a In addition, the living anionic polymerization of D3 was controlled using the functionalized initiators 3-[(N-benzyl-N-methyl)amino]-1-propyllithium and 3-(t-butyldimethylsilyloxy)-1-propyllithium. (Abstract shortened by UMI.)
590 $a School code: 0247.
650 4 $a Chemistry, Polymer. $3 1018428
690 $a 0495
710 2 0 $a Virginia Polytechnic Institute and State University. $3 1017496
773 0 $t Dissertation Abstracts International $g 66-05B.
790 1 0 $a Long, Timothy E., $e advisor
790 $a 0247
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3177332