Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films

Detalhes bibliográficos
Autor(a) principal: Mouquinho, Ana Isabel Machado
Data de Publicação: 2012
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10362/8089
Resumo: Dissertation to obtain the degree of master in Bioorganic
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spelling Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC filmsMonomer synthesisMicrowave irradiationSolventless reactionsLiquid crystalPDLCElectro-optical propertiesDissertation to obtain the degree of master in BioorganicPolymer dispersed liquid crystal (PDLC) films consist, commonly, on nematic liquid crystal domains dispersed in a polymeric matrix. These composites can be switched electrically from an opaque scattering state to a highly transparent state by an applied electric field. The molecular structure of the polymerisable monomers that can be incorporated as polymeric matrix plays an important role in the performance of PDLCs. Therefore, the aims of this work were to design and synthesise several new monomers that could be polymerised photochemically and thermally to be incorporated as polymeric matrices in PDLCs and investigate the influence of the molecular structure on the performance of these devices. Several monomers were synthesised in order to achieve better miscibility between the liquid crystal and the monomers during preparation of PDLC films. For this purpose, the monomers were synthesised so as to mimic some structural elements of the E7 liquid crystal molecules. Thus, several aromatic mono- and dimethacrylates with and without a linear chain spacer with five methylene units, as well as vinylic monomers were successfully synthesised. Mild and solvent freeprocedures were developed with reaction times as short as 1 to 5 min, using microwave irradiation. The structures of all isolated monomers were supported by 1H NMR, 13C NMR and FTIR spectroscopy, elemental analysis and melting point. Of all the synthesised monomers, the monomers that included in their structure aromatic rings bearing a cyano group and/or a linear chain spacer with five methylene units were fully characterised due to their higher molecular structure affinity with the E7 liquid crystal molecules. In order to evaluate the effect of these groups, these monomers were compared with those of similar structure but without the respective groups. Thus, DSC and POM with temperature ramps were used for the thermal characterisation of the monomers. The structural morphologies of the polymeric matrices were characterised by SEM. The monomers were also copolymerised with glycidyl methacrylate and the molecular weights of the resulting polymers were evaluated by GPC. The electro-optical properties of the PDLC films were determined by measuring the voltage dependence on the transmitted light.Fundação para a Ciência e Tecnologia - Project PTDC/CTM/69145/2006Faculdade de Ciências e TecnologiaRUNMouquinho, Ana Isabel Machado2012-11-06T12:09:18Z20122012-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/8089enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-03-11T03:40:32Zoai:run.unl.pt:10362/8089Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:17:56.234899Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
title Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
spellingShingle Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
Mouquinho, Ana Isabel Machado
Monomer synthesis
Microwave irradiation
Solventless reactions
Liquid crystal
PDLC
Electro-optical properties
title_short Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
title_full Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
title_fullStr Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
title_full_unstemmed Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
title_sort Selective synthesis under microwave irradiation of new monomers for potential applications in PDLC films
author Mouquinho, Ana Isabel Machado
author_facet Mouquinho, Ana Isabel Machado
author_role author
dc.contributor.none.fl_str_mv RUN
dc.contributor.author.fl_str_mv Mouquinho, Ana Isabel Machado
dc.subject.por.fl_str_mv Monomer synthesis
Microwave irradiation
Solventless reactions
Liquid crystal
PDLC
Electro-optical properties
topic Monomer synthesis
Microwave irradiation
Solventless reactions
Liquid crystal
PDLC
Electro-optical properties
description Dissertation to obtain the degree of master in Bioorganic
publishDate 2012
dc.date.none.fl_str_mv 2012-11-06T12:09:18Z
2012
2012-01-01T00:00:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10362/8089
url http://hdl.handle.net/10362/8089
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Faculdade de Ciências e Tecnologia
publisher.none.fl_str_mv Faculdade de Ciências e Tecnologia
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
repository.mail.fl_str_mv
_version_ 1799137826092089344

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