Molecular design of main-chain liquid crystalline polyolefin

Naofumi Naga, Masato Sone, Keiichi Noguchi, Shigemitsu Murase

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Liquid crystalline features of polyolefin have been clearly observed in a polyolefin of poly(methlene-1,3-cyclopentane) (PMCP) obtained from cyclization polymerization of 1,5-hexadiene (HD) using metallocene catalysts. PMCP clearly shows fluidity and birefringence above the glass transition temperature under the ambient conditions, at around room temperature and normal pressure. First order structures of PMCP, such as cyclization selectivity of polymerized HD units, stereo-regularity of 1,3-cyclopentane units, and molecular weight, affect the liquid crystalline features of PMCP. High cyclization selectivity and trans-rich structure of 1,3-cyclopentane units are necessary to induce the liquid crystalline phase. Polarized optical micrographs of PMCP show Schlieren-like texture, which indicates nematic liquid crystalline phase. Clear diffraction patterns are observed in wide-angle X-ray diffraction analysis below the isotropization temperatures. The isotropization temperature decreases with decreasing of molecular weight of PMCP. PMCP with the higher molecular weight takes the longer time for liquid crystallization from isotropic phase in the cooling process. We have also synthesized an optically active PMCP with an optically active metallocene catalyst in the presence of a chain transfer reagent to control the molecular weights of the resulting polymers. Optically active PMCP with relatively high molecular weight shows finger print texture which indicates cholesteric liquid crystal. On the other hand, decreasing molecular weight the optically active PMCP induces nematic liquid crystalline phase.

Original languageEnglish
Title of host publicationLiquid Crystals XIII
DOIs
Publication statusPublished - 2009 Nov 18
EventLiquid Crystals XIII - San Diego, CA, United States
Duration: 2009 Aug 22009 Aug 5

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7414
ISSN (Print)0277-786X

Conference

ConferenceLiquid Crystals XIII
CountryUnited States
CitySan Diego, CA
Period09/8/209/8/5

Keywords

  • 1,5-hexadiene
  • Cholesteric liquid crystal
  • Cyclizaion polymerization
  • Liquid crystal
  • Metallocene catalyst
  • Nematic liquid crystal
  • Optical active
  • Polyolefin

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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  • Cite this

    Naga, N., Sone, M., Noguchi, K., & Murase, S. (2009). Molecular design of main-chain liquid crystalline polyolefin. In Liquid Crystals XIII [741404] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7414). https://doi.org/10.1117/12.825051