Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


case1056133548.pdf (8.72 MB)

ETD Abstract Container

Abstract Header

Main chain liquid crystalline polyethers based on conformational isomerism

Zuber, Mohammad
http://rave.ohiolink.edu/etdc/view?acc_num=case1056133548

Abstract Details

1992, Doctor of Philosophy, Case Western Reserve University, Macromolecular Science.
The synthesis of 1-(4-hydroxyphenyl)-2-(2-chloro-4-hdyroxyphenyl)ethane (ClBPE) a flexible mesogen and polyethers and copolyethers based on ClBPE and α,ω-dibromoalkanes containing from 4 to 20 methylene units are described. With some exceptions, most of the homopolymers display monotropic or virtual mesophases. The virtual isotropic-nematic (Tin) and nematic-nematic transitions (Tn1n2) and corresponding thermodynamice parameters were determined from the copolymerization experiment. The synthesis of 1-(4-hydroxyphenyl)-2-(2-fluoro-4-hydroxyphenyl)ethane (FBPE), 1-(4-hydroxyphenyl)-2-(2-bromo-4-hydroxyphenyl)ethane (BrBPE) and 1-(4-hydroxyphenyl)-2-(2-trifluoromethyl-4-hydroxyphenyl)ethane (CF3BPE) have been described. The homopolymers based on these mesogens (RBPE, where R = F, Cl, Br and CF3) and 1,5-dibromopentane (RBPE-5) and 1,8-dibromooctane (RBPE-8) and the corresponding copolymers based on various ratios of 1,5-dibromopentane and 1,8-dibromooctane (RBPE-5/8(A/B)) are synthesized. The isotropic-nematic transition temperatures and the thermodynamic parameters of RBPE-5 and RBPE-8 were compared with corresponding polyethers based on 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane (MBPE) from the literature. The copolymers based on 1-(4-hydroxyphenyl)-2-(2-R-4 -hydroxyphenyl)ethane (RBPE) where R = F, Cl and CH3 and flexible spacers containing odd number of methylene units (5, 7 and 9) were synthesized for the characterization of low temperature nematic (n2) phase. The synthesis and characterization of copolyethers based on FBPE and various ratios of 1,8-dibromooctane and 1,12-dibromododecane (FBPE-8/12(X/Y)), and of copolymers based on 50/50 molar ratio of 1,8-dibromooctane and 1,12-dibromododecane with various ratios of 1,2-bis(4-hydroxyphenyl)ethane (BPE) and FBPE (BPE/FBPE(A/B)-8/12(50/50)) are presented. The synthesis of 4,4′-bis (2-(4-hydroxyphenyl)ethyl) benzene (PEB), of the polyethers based on PEB and α,ω-dibromalkanes (PEB-X, where X represents the number of methylene units in the flexible spacer and is equal to 5, 7, 8, 9, 10 and 12), of the polyether based on BPE and 1,9-dibromononane (BPE-9) and of copolyethers based on 1,9-dibromononane with various ratios of BPE to PEB (BPE/PEB(A/B)-9, where A/B is the molar ratio of BPE to PEB) are presented. (Abstract shortened with permission of author.
Virgil Percec (Advisor)
380 p.
Chemistry, Polymer
Main chain liquid crystalline polyethers based conformational isomerism

Recommended Citations

Citations

  • Zuber, M. (1992). Main chain liquid crystalline polyethers based on conformational isomerism [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1056133548

    APA Style (7th edition)

  • Zuber, Mohammad. Main chain liquid crystalline polyethers based on conformational isomerism. 1992. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1056133548.

    MLA Style (8th edition)

  • Zuber, Mohammad. "Main chain liquid crystalline polyethers based on conformational isomerism." Doctoral dissertation, Case Western Reserve University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1056133548

    Chicago Manual of Style (17th edition)

case1056133548
524
© 1992, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.