| In this dissertation, we design and synthesize Mesogen-Jacketed liquid crystal polymers with cleaning point for purpose, successfully synthesized a series of polymers based on 2-vinylterephthalic acid, mainly focuses on studying the effection of alkoxy terminal group density and category on the liquid crystalline behavior of poly(ethylene terephthalate).1. It discussed the influence of single alkoxy terminal group with different length on liquid-crystalline behavior of Mesogen-Jacketed liquid crystal polymers. A kind of polymer with different length of terminal groups were designed and synthesized with the name of poly{2,5-bis [(4-alkoxy benzyl) oxycarbonyl] styrene} (P-4-OCmH2m+1 m was the number of the carbons in the alkoxy groups, m =10, 12, 14, 16, 18), which is based on PMBCS. The molecular characterizations of the polymers was performed with 1H NMR and gel permeation chromatography (GPC), The phase structures and transition behaviors of the polymers were investigated by differential scanning calorimetry (DSC), polarized optical microscope (POM), thermogravimetric analysis (TGA). The results show that P-4-OCmH2m+1 can′t exhibit liquid crystalline behavior during the process of heating or cooling but exhibit crystalline behavior. The crystalline melting temperature increase by degrees with the increasing length of alkoxy terminal group.2. It discussed the influence of two or three alkoxy terminal groups with different length on liquid-crystalline behavior of Mesogen-Jacketed liquid crystal polymers. Two kind of polymers with different length of terminal groups are designed and synthesized with the name of poly{2, 5-bis [(3, 5-dialkoxy benzyl) oxycarbonyl] styrene}[P-(3, 5)-di-OCmH2m+1], poly{2, 5-bis[(3, 4, 5-trialkoxy benzyl) oxycarbonyl] styrene}[P-(3, 4, 5)-tri-OCmH2m+1], (m was the number of the carbons in the alkoxy groups, m =10, 12, 14, 16, 18). The molecular characterizations of the polymers was performed with 1H NMR and gel permeation chromatography (GPC), The phase structures and transition behaviors of the polymers were investigated by differential scanning calorimetry (DSC), polarized optical microscope (POM), thermogravimetric analysis (TGA) and one-dimensional wide-angle X-ray diffraction (1D-WAXD). The results shows that both P-(3, 5)-di-OCmH2m+1 and P-(3, 4, 5)-tri-OCmH2m+1 exhibit crystalline behavior and liquid crystalline behavior during the process of heating or cooling. There are no cleaning point appeared before decomposition temperature. The crystalline melting temperature increase by degrees with the increasing length of alkoxy terminal group.3. It discussed the influence of single swallow-tailed alkoxy terminal group with different length on liquid-crystalline behavior of Mesogen-Jacketed liquid crystal polymers. A kind of polymer with different length of terminal groups are designed and synthesized with the name of poly{2, 5-bis [(2- propyl) oxycarbonyl] styrene}, poly{2, 5-bis [(3-amyl) oxycarbonyl] styrene}, poly{2, 5-bis [(4-heptyl) oxycarbonyl] styrene}[P-4-OCH(CmH2m+12], m was the number of the carbons in the alkoxy groups, m =1, 2, 3). The molecular characterizations of the polymers was performed with 1H NMR and gel permeation chromatography (GPC), The phase structures and transition behaviors of the polymers were investigated by differential scanning calorimetry (DSC), polarized optical microscope (POM), thermogravimetric analysis (TGA) and one-dimensional wide-angle X-ray diffraction (1D-WAXD). The results shows that P-4-OCH(CmH2m+12 exhibit liquid crystalline behavior during the process of heating or cooling and cleaning point appeared before decomposition temperature. The glass-transition temperature and cleaning point temperature decrease by degrees with the increasing length of alkoxy terminal group.Sum up, it is great of the influence of alkoxy terminal group on liquid-crystalline behavior of MJLCP. Single linearity alkoxy terminal group baffle the formation of liquid crystalline phase; Multi-linearity alkoxy terminal group can't destroy the formation of liquid crystalline phase and no cleaning point appeared under decomposition temperature; Single swallow-tailed alkoxy terminal group affect the liquid crystalline phase and cleaning point appeard.
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