Synthesis and phase behaviour of a homologous seriesof polymethacrylate-based side-chain liquid crystal polymers
The homologous series of side chain liquid crystal polymers, the poly[¿-(4-methoxyazobenzene-4¿-oxy)alkyl methacrylate]s, has been prepared in which the length of the flexible alkyl spacer has been varied from 3 to 11 methylene units. All the polymers exhibit liquid crystalline behaviour. The propyl...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/31801 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/31801 |
| Access Level: | acceso abierto |
| Palabra clave: | Liquid crystals Side chain liquid crystal polymer Smectic A phase Alkyl spacers Flexible spacer Homologous series Liquid-crystalline Side chain liquid crystal polymers Side-chains Smectic layers Smectic phase Smectic-A X ray diffraction Liquid crystal polymers MAQUINAS Y MOTORES TERMICOS |
| Sumario: | The homologous series of side chain liquid crystal polymers, the poly[¿-(4-methoxyazobenzene-4¿-oxy)alkyl methacrylate]s, has been prepared in which the length of the flexible alkyl spacer has been varied from 3 to 11 methylene units. All the polymers exhibit liquid crystalline behaviour. The propyl and butyl members show exclusively nematic behaviour. The pentyl, hexyl, octyl and decyl members show a nematic and a smectic A phase while the heptyl, nonyl and undecyl homologues exhibit only a smectic A phase. The smectic A phase has been studied using X-ray diffraction and assigned as a smectic A 1 phase in which the side chains are fully overlapped and the backbones are confined to lie between the smectic layers. For the nonyl member an incommensurate smectic phase is observed. The dependence of the transition temperatures on the length of the flexible spacer is understood in terms of the average shapes of the side chains. © 2012 Elsevier Ltd. All rights reserved. |
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