Molecular design of main-chain liquid crystalline polyolefin

Naofumi Naga; Masato Sone; Keiichi Noguchi; Shigemitsu Murase

doi:10.1117/12.825051

20 August 2009 Molecular design of main-chain liquid crystalline polyolefin

Naofumi Naga, Masato Sone, Keiichi Noguchi, Shigemitsu Murase

Proceedings Volume 7414, Liquid Crystals XIII; 741404 (2009) https://doi.org/10.1117/12.825051
Event: SPIE Photonic Devices + Applications, 2009, San Diego, California, United States

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.

Citation Download Citation

Naofumi Naga, Masato Sone, Keiichi Noguchi, and Shigemitsu Murase "Molecular design of main-chain liquid crystalline polyolefin", Proc. SPIE 7414, Liquid Crystals XIII, 741404 (20 August 2009); https://doi.org/10.1117/12.825051

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available