Accession Number : ADA242400

Title :   Molecular Engineering of Liquid Crystal Polymers by Living Polymerization. 17. Characterization of Poly(10-((4-Cyano-4'-Biphenyl)oxy) decanyl Vinyl Ether)s by 1-D and 2-D H-NMR Spectroscopy

Descriptive Note : Technical rept.,

Corporate Author : CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF MACROMOLECULAR SCIENCE

Personal Author(s) : Percec, Virgil ; Lee, Myongsoo ; Rinaldi, Peter L. ; Litman, Vincent E.

PDF Url : ADA242400

Report Date : 30 OCT 1991

Pagination or Media Count : 14

Abstract : Since the first examples of mesogenic vinyl ethers and liquid crystalline poly(vinyl ether)s were reported from our laboratory, several research groups became actively engaged in the synthesis of liquid crystalline poly(vinyl ether)s mainly because they can be polymerized by living cationic mechanism. So far, we have elucidated the influence of molecular weight on the phase transitions of poly(omega-((4-cyano-4'-biphenyl)oxy)alkyl vinyl ether)s with alkyl groups from ethyl to undecanyl. Binary copolymerization experiments performed with the same monomers at constant copolymer molecular weight allowed the molecular design of nematic, smectic A and reentrant nematic mesophases. Similar homopolymerization and copolymerization experiments were used to tailor make polymers exhibiting a chiral smectic C mesophase. In addition, it has been shown that many functional mesogenic vinyl ethers can be polymerized by our preferred initiating system CF3SO3H/S(CH3)2 in CH2Cl2(9). The experiments described so far required only a good control over the degree of polymerization and polydispersity of the polymer.

Descriptors :   *CATIONS, SYNTHESIS, MOLECULES, PHASE TRANSFORMATIONS, POLYMERS, POLYMERIZATION, MOLECULAR WEIGHT, COPOLYMERS, LIQUID CRYSTALS, ENGINEERING, ETHERS, MONOMERS, LIFE(BIOLOGY), ALKYL RADICALS, HOMOGENEITY, VINYL RADICALS, COPOLYMERIZATION, POLARIZATION

Subject Categories : Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE