Accession Number : ADA183705

Title :   Synthesis and Characterization of Liquid Crystalline Copolymethacrylates, Copolyacrylates and Copolysiloxanes Containing 4-Methoxy-4'-Hydroxy-alpha-Methylstilbene and 4-Hydroxy-4'-Methoxy-alpha-Methylstilbene Constitutional Isomers as Side Groups.

Descriptive Note : Technical rept.,

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

Personal Author(s) : Percec,Virgil ; Hsu,Chain S ; Tomazos,Dimitris

PDF Url : ADA183705

Report Date : Jan 1987

Pagination or Media Count : 62

Abstract : The synthesis of methacrylates and acrylates containing 4-methoxy-4'-hydroxy-alpha methylstilbene and 4-hydroxy-4'-methoxy-alpha-methylstilbene constitutional isomers attached to the polymerizable group through flexible spacers containing eleven, eight, six, three and respectively two methlenic units is described. The radical copolymerization of a 1/2 or 2/1 mole ratio of the two constitutional isomeric monomers led to thermotropic side-chain liquid crystalline polymers in all cases. The synthesis of copolysiloxanes based on the same constitutional isomeric mesogens as side groups, and flexible spacers containing eleven, eight, six, five and respectively three methylenic units is also described. All polymers were characterized by differential scanning calorimetry and optical polarization microscopy. The polymers containing eleven methylenic units in the spacer exhibit SC mesomorphism, while the other polymers are nematic. Copolymetharcrylates do not undergo side-chain crystallization. Only the copolyacrylate containing eleven methylenic units in the spacer exhibits side chain crystallization. All the copolysiloxanes present side-chain crystallization. The number of melting transitions presented by these polymers decreases with the decrease of their spacer length.

Descriptors :   *ACRYLATES, *COPOLYMERS, *SILOXANES, ACRYLATES, CALORIMETRY, COPOLYMERIZATION, CRYSTALLIZATION, ISOMERS, LIQUID CRYSTALS, MELTING, METHACRYLATES, MICROSCOPY, MONOMERS, OPTICAL ANALYSIS, POLARIZATION, POLYMERIZATION, POLYMERS, RATIOS, SCANNING, TRANSITIONS, SYNTHESIS(CHEMISTRY), CHEMICAL PROPERTIES, STILBENES, METHYL RADICALS

Subject Categories : Polymer Chemistry
      Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE