Molecular design of main-chain liquid crystalline polyolefin

Naofumi Naga, Masato Sone, Keiichi Noguchi, Shigemitsu Murase

研究成果: Conference contribution


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.

ホスト出版物のタイトルLiquid Crystals XIII
出版物ステータスPublished - 2009 11 18
イベントLiquid Crystals XIII - San Diego, CA, United States
継続期間: 2009 8 22009 8 5


名前Proceedings of SPIE - The International Society for Optical Engineering


ConferenceLiquid Crystals XIII
United States
San Diego, CA

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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  • これを引用

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