Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate

This thesis is primarily concerned with the synthesis of a new thermotropic liquid crystalline monomer and its characterisation by using elemental analysis, spectroscopic analysis and thermal analysis techniques. A new thermotropic liquid crystalline monomer, 4-methylphenyl 4-[2- (vinyloxy)ethox...

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Main Author: Zain, Mohamad Hussin
Format: Thesis
Language:English
English
Published: 2000
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/9084/1/FSAS_2000_18%20IR.pdf
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spelling my-upm-ir.90842024-03-20T23:56:50Z Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate 2000-12 Zain, Mohamad Hussin This thesis is primarily concerned with the synthesis of a new thermotropic liquid crystalline monomer and its characterisation by using elemental analysis, spectroscopic analysis and thermal analysis techniques. A new thermotropic liquid crystalline monomer, 4-methylphenyl 4-[2- (vinyloxy)ethoxy]benzoate (4MP4VEB) was synthesised by reacting 4- methylphenyl 4-hydroxybenzoate (4MP4HB) with 2-chloro-ethyl-vinyl ether in acetonic solution. The compound 4MP4HB as a mesogenic group was prepared from the reaction of p-hydroxybenzoic acid and p-cresol. The mesogenic group (4MP4HB) was also used to synthesise the other thermotropic liquid crystalline compound namely 4-methylphenyl 4-(3-hydroxypropoxy)benzoate (4MP4HPB) but without a monomer terminal.The attempted synthesis of other liquid crystalline monomer with a varying spacer length using a different approach only ended up with a precursor compound. Two precursors, namely 4-[4-(allyloxy)butoxy]benzoic acid (4ABBA) and 4-(allyloxy)benzoic acid (4ABA) were successfully synthesised for the preparation of thermotropic liquid crystals with an allyl group as a monomer terminal. The compound 4ABBA is a precursor that has a spacer linkage, while 4ABA is without a spacer linkage. The liquid crystalline compound and the synthesised precursors were characterised by elemental, spectroscopic and thermal analyses. The observation of thermal properties and liquid crystallinities under polarising microscope revealed that the compound 4MP4VEB exhibited the like-mosaic defect texture of nematic mesophase, while the compound 4MP4HPB exhibited the focal-conic texture of smectic A mesophase. Thermotropism - Research 2000-12 Thesis http://psasir.upm.edu.my/id/eprint/9084/ http://psasir.upm.edu.my/id/eprint/9084/1/FSAS_2000_18%20IR.pdf text en public masters Universiti Putra Malaysia Thermotropism - Research Faculty of Environmental Studies Silong, Sidik English
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
English
advisor Silong, Sidik
topic Thermotropism - Research


spellingShingle Thermotropism - Research


Zain, Mohamad Hussin
Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
description This thesis is primarily concerned with the synthesis of a new thermotropic liquid crystalline monomer and its characterisation by using elemental analysis, spectroscopic analysis and thermal analysis techniques. A new thermotropic liquid crystalline monomer, 4-methylphenyl 4-[2- (vinyloxy)ethoxy]benzoate (4MP4VEB) was synthesised by reacting 4- methylphenyl 4-hydroxybenzoate (4MP4HB) with 2-chloro-ethyl-vinyl ether in acetonic solution. The compound 4MP4HB as a mesogenic group was prepared from the reaction of p-hydroxybenzoic acid and p-cresol. The mesogenic group (4MP4HB) was also used to synthesise the other thermotropic liquid crystalline compound namely 4-methylphenyl 4-(3-hydroxypropoxy)benzoate (4MP4HPB) but without a monomer terminal.The attempted synthesis of other liquid crystalline monomer with a varying spacer length using a different approach only ended up with a precursor compound. Two precursors, namely 4-[4-(allyloxy)butoxy]benzoic acid (4ABBA) and 4-(allyloxy)benzoic acid (4ABA) were successfully synthesised for the preparation of thermotropic liquid crystals with an allyl group as a monomer terminal. The compound 4ABBA is a precursor that has a spacer linkage, while 4ABA is without a spacer linkage. The liquid crystalline compound and the synthesised precursors were characterised by elemental, spectroscopic and thermal analyses. The observation of thermal properties and liquid crystallinities under polarising microscope revealed that the compound 4MP4VEB exhibited the like-mosaic defect texture of nematic mesophase, while the compound 4MP4HPB exhibited the focal-conic texture of smectic A mesophase.
format Thesis
qualification_level Master's degree
author Zain, Mohamad Hussin
author_facet Zain, Mohamad Hussin
author_sort Zain, Mohamad Hussin
title Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
title_short Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
title_full Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
title_fullStr Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
title_full_unstemmed Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
title_sort synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate
granting_institution Universiti Putra Malaysia
granting_department Faculty of Environmental Studies
publishDate 2000
url http://psasir.upm.edu.my/id/eprint/9084/1/FSAS_2000_18%20IR.pdf
_version_ 1804888542681235456