Synthesis Of Liquid Crystalline Polymers Via Electrophilic Reaction Under Eaton Reagent As The Media Conditions

Liquid crystal polymers have broad application prospects in highstrength and high modulus materials, digital and image displayapplication and information storage because of its unique rheologicalproperties of the liquid crystal phase behavior as well as uniquefunctional properties. Synthesis and phase transition of liquid crystalpolymer is a hot topic in polymer science. In this thesis, four kinds of richelectric monomer and aromatic cyclic ether ketone dimer with rigidstructure have been successfully synthesized. On this basis, a series ofnovel liquid crystal polymers have been successfully synthesized viaelectrophilic reaction under eaton reagent as a dehydrating agent. Detailsare as follows:Adoption of high-temperature nucleophilic reaction, four richelectric monomer have been successfully synthesized by4,4-dichlorodiphenyl sulfone or4,4-dichloro benzophenone and phenol or cresol. Thestructures of four rich electric monomers are confirmed by IR, NMRanalyses. A series of new liquid crystalline polymer has been synthesizedfrom rich electric monomers and diacid, such as pimelic acid, suberic acid,azelaic acid, sebacic acid or lauric acid via electrophilic reaction usingEaton reagent as dewatering conditions. The series of liquid crystalpolymer materials were characterized by a combination of XRD，DSC，TGA and NMR analyses. The novel polymer materials have nematicliquid crystalline phase, and have excellent thermal stability, thetemperatures of5%weight loss are above450℃under nitrogenatmosphere.In chapter4, a kind of rigid cyclic aryl ether ketone dimer have beensynthesized from4,4-difluoro benzophenone and phenol A vianucleophilic substitution reaction at150℃under the condition of“pseudo high dilution” and characterized by a combination of IR, NMR,and GPC analyses. In order to provide a flexible chain for discoticcompound,3,5-dioctyloxy benzoic acid and3,4,5-trioctyloxy benzoicacid were synthesized from bromo-octane and phenyl benzoate. Themodel discotic compound was synthesized from aromatic cyclic dimer and acetic acid via electrophilic reaction under Eaton reagent andcharacterized by NMR. The study on the synthesis and application ofdiscotic compound with rigid cyclic core and flexible branched chainunder Eaton reagent is in progress.