Transformation of a Monotropic Mesophase into an Enantiotropic Mesophase by Copolymerization of the Parent Polymers' Monomer Pair Containing Constitutional Isomeric Mesogenic Side Groups. Preprint

Abstract

The synthesis and the mesomorphic behavior of poly(methylsiloxane)s containing 4-methoxy-4'-hydroxy-trans-alpha-methylstilbene (4-n-PS) and 4-hydroxy-4'-methoxy-trans-alpha-methylstilbene (4'-n-PS) connected to the backbone by flexible spacers containing three, six and eleven (n = 3, 6, 11) methylene units, and of some copolymers based on these two constitutional isomeric mesogenic side groups (4,4' (A/B)-n-coPS) is described. The copolymers derived from structural units whose homopolymers displayed enantiotropic mesophases (4,4'(A/B)-3-coPS and 4,4' (A/B)-11-coPS) exhibited a depression of both mesomorphic and crystalline phase transition temperatures. However, the 4, 4' (50/50)-6-coPS copolymers, derived from structural units whose homopolymers (4-6-PS and 4'-6-PS) displayed nematic monotropic mesophases, exhibited an enantiotropic nematic mesophase. Liquid crystal polymers, Monotropic, Enantiotropic.

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Document Details

Document Type
Technical Report
Publication Date
Jan 20, 1989
Accession Number
ADA208782

Entities

People

  • D. Tomazos
  • Virgil Percec

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  • Case Western Reserve University

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  • Chemistry

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  • Polymer Science and Technology

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