Please use this identifier to cite or link to this item: https://scholarbank.nus.edu.sg/handle/10635/15340
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dc.titleMolecular design, thin film polymerization and characterization of fluorinated liquid crystalline polymers
dc.contributor.authorTEOH MAY MAY
dc.date.accessioned2010-04-08T10:52:30Z
dc.date.available2010-04-08T10:52:30Z
dc.date.issued2006-08-08
dc.identifier.citationTEOH MAY MAY (2006-08-08). Molecular design, thin film polymerization and characterization of fluorinated liquid crystalline polymers. ScholarBank@NUS Repository.
dc.identifier.urihttp://scholarbank.nus.edu.sg/handle/10635/15340
dc.description.abstractThe aim of this study was to synthesize fluorinated polyesters and poly(ester-amide)s and attempt to discover novel thin film liquid crystalline polymers (LCPs) by thin film polymerization. Detailed examination of ANA/AAA/perfluoroalkyl flexible spacers revealed that systems containing short perfluoroalky spacers (n = 2, 3) tended to remain in liquid crystal (LC) phase, while a long perfluoroalky spacer (n = 8) tended to crystallize. Both simulation and experimental results confirmed that ABA/AAA/TFTA (para) has the greatest tendency to yield LC formation, followed by ABA/AAA/TFIA (meta) and ABA/AAA/TFPA (ortho). The average Avrami exponent, n, was ~1.2, suggesting a mesophase transition in ABA/MH/TFTA film, while DSC results confirmed the phase transition in ABA/HQ/TFTA as crystali? nematici? isotropic. Optical microscope study showed that the surface microcracks formed during rapid quenching. The ABA/MH/TFTA film exhibits disclination strengths with S = +1 and - A?. However, disclination strengths with S = A?1 were observed in ABA/MH/TFIA system. Overall, all the above systems satisfied the minimum requirement, persistence ratio larger than 6.42, for LC formation by molecular science simulation.
dc.language.isoen
dc.subjectthermotropic liquid crystalline polymers, fluorine, polyesters, poly(ester-amide)s, persistence ratio , in-situ thin film polymerization
dc.typeThesis
dc.contributor.departmentCHEMICAL & BIOMOLECULAR ENGINEERING
dc.contributor.supervisorCHUNG TAI-SHUNG, NEAL
dc.description.degreePh.D
dc.description.degreeconferredDOCTOR OF PHILOSOPHY
dc.identifier.isiutNOT_IN_WOS
Appears in Collections:Ph.D Theses (Open)

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