Accession Number : ADA183435

Title :   Liquid Crystalline Polymers Containing Heterocycloalkane Mesogenic Groups. 5. Synthesis of Biphasic Chiral-Smectic Polysiloxanes Containing 2,5-Disubstituted-1,3-Dioxane and 2,5-Disubstituted-1,3,2-Dioxaborinane Based Mesogenic Groups.

Descriptive Note : Technical rept.,

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

Personal Author(s) : Hahn,Bruce ; Percec,Virgil

Report Date : 1987

Pagination or Media Count : 40

Abstract : The synthesis of side-chain liquid crystalline polysiloxanes containing chiral mesogenic side-groups, is presented. Differential scanning calorimetry and optical polarization microscopy revealed chiral smectic mesomorphism for all polymers. The last two polymers present also a chiral smectic-C mesophase. All copolymers exhibit two glass transition temperatures; one due to the independent motion of the main chain, the other due to the cooperative but independent motion of the side-groups. Therefore, these liquid crystalline copolymers are biphasic systems resembling the behavior of phase separated graft copolymers, i.e., they exhibit a micro-phase separated morphology containing main-chain and side-chain domains.

Descriptors :   *COPOLYMERS, *SILOXANES, *POLYMERS, *ALKANES, CALORIMETRY, CHAINS, DOMAIN WALLS, GLASS, GRAFT POLYMERIZATION, LIQUID CRYSTALS, MICROSCOPY, MOTION, OPTICAL ANALYSIS, POLARIZATION, SCANNING, SEPARATION, TRANSITION TEMPERATURE, SYNTHESIS(CHEMISTRY)

Subject Categories : Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE