Azobenzene-Based Main-Chain Liquid Crystalline Polymers Bearing Periodically Installed Alkyl, PEG, or Fluoroalkyl Segments and Photoisomerization Studies

Ogunsola Orodepo, G and Bhoje Gowd, E and Ramakrishnan, S (2024) Azobenzene-Based Main-Chain Liquid Crystalline Polymers Bearing Periodically Installed Alkyl, PEG, or Fluoroalkyl Segments and Photoisomerization Studies. In: Polymer-Plastics Technology and Materials .

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Abstract

In the present study, liquid crystalline polymers (LCPs) were prepared by melt-transesterification of azobenzene-bearing diols and diethyl malonate (DEM) derivatized monomers. The effect of the nature and length of the installed pendant segments on the mesomorphic properties of the prepared LCPs was investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized optical microscopy (POM) studies. The formation of layered morphology was inferred from X-ray scattering analysis arising from the colocation of rigid azobenzene moieties in one layer and the flexible pendant segments in alternate layers due to the zigzag folding of the polymer backbone. The linear variation of the interlamellar spacing with the number of carbon atoms in the pendant alkyl segments corroborates the proposed zigzag backbone folding in the polymers. The rate constant values obtained from the photoisomerization studies of the isomeric polymers and model compound, which are in the same ballpark, reveal that the photoisomerization process of such polymers is not affected by the position or size of the azobenzene unit. © 2024 Taylor & Francis Group, LLC.

Item Type:	Journal Article
Publication:	Polymer-Plastics Technology and Materials
Publisher:	Taylor and Francis Ltd.
Additional Information:	The copyright for this article belongs to the publisher.
Keywords:	Crystalline materials; Elastomers; Photoisomerization; X ray diffraction analysis; X ray scattering, Cis-trans photoisomerization; Crystalline polymers; Diethyl malonates; Foldings; Liquid crystalline; Main chains; Main-chain liquid crystalline polymers; Melt transesterification; Photoisomerizations; Polymer bearings, Azobenzene
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	17 Oct 2024 04:25
Last Modified:	17 Oct 2024 04:25
URI:	http://eprints.iisc.ac.in/id/eprint/86340

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