Keyword Search:

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

Zain, Mohamad Hussin (2000) Synthesis and characterisation of thermotropic liquid crystalline monomer : 4-methylphenyl 4-[2-(vinyloxy) ethoxy]benzoate. Masters thesis, Universiti Putra Malaysia.

[img] PDF
1099Kb

Abstract

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.

Item Type:Thesis (Masters)
Subject:Thermotropism - Research
Chairman Supervisor:Sidik Bin Silong, PhD
Call Number:FSAS 2000 18
Faculty or Institute:Faculty of Environmental Studies
ID Code:9084
Deposited By: Tuan Norasiah Tuan Yaacob
Deposited On:06 Jan 2011 02:39
Last Modified:28 Oct 2014 01:32

Repository Staff Only: Edit item detail

 
 
 
 

Universiti Putra Malaysia Institutional Repository is powered by EPrints 3 which is developed by the School of Electronics and Computer Science at the University of Southampton. More information and software credits.
Universiti Putra Malaysia Institutional Repository supports OAI 2.0 with a base URL of http://psasir.upm.edu.my/cgi/oai2
Best viewed using IE version 7.0 (and above) Mozilla Firefox version 3 (and above) with the resolution of 1024 x 768.