Structure–property relationship of a series of novel mesogen-jacketed liquid-crystalline polymers containing semirigid side chain with different numbers of alkoxy terminal groups
Structure–property relationship of a series of novel mesogen-jacketed liquid-crystalline polymers containing semirigid side chain with different numbers of alkoxy terminal groups
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DOI：
10.1016/j.polymer.2009.12.004
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发表时间：
2010-01
期刊：
影响因子：
4.6
通讯作者：
Chang-an Yang;Qian Tan;G. Zhong;He-Lou Xie;Hailiang Zhang;E. Chen;Qifeng Zhou
中科院分区：
文献类型：
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作者：
Chang-an Yang;Qian Tan;G. Zhong;He-Lou Xie;Hailiang Zhang;E. Chen;Qifeng Zhou
合成了一系列乙烯基单体2，5-双[(4-甲氧基苄基)氧羰基]苯乙烯(MBCS)、2，5-双[(3，5-二甲氧基苄基)氧羰基]苯乙烯(DMBCS)和2，5-双[(3，4，5-三甲氧基苄基)氧羰基]苯乙烯(TMBCS)，并通过自由基聚合法进行了聚合。系统地改变了半刚性侧链末端基团的数量，以考察它们的数量对产物形成中间相能力的影响。单体的化学结构经元素分析、核磁共振氢谱和核磁共振碳谱确证。用核磁共振氢谱、凝胶渗透色谱(GPC)对聚合物进行了表征。用差示扫描量热仪(DSC)、偏光显微镜(PLM)、一维和二维广角X射线衍射仪(WAXD)研究了其相结构和相变行为。实验结果表明，聚合物的中间相形成能力随着侧链刚性的降低而降低，随烷氧基端基数目的增加而增加，且所有高相对分子质量的聚合物都具有稳定的柱状向列相(ΦN)。
A series of vinyl monomers, 2, 5-bis [(4-methoxy benzyl) oxycarbonyl] styrene (MBCS); 2, 5-bis [(3, 5-dimethoxy benzyl) oxycarbonyl] styrene (DMBCS) and 2, 5-bis [(3, 4, 5-trimethoxy benzyl) oxycarbonyl] styrene (TMBCS) were synthesized and polymerized via free radical polymerization. The terminal groups of the semirigid side chain were systematically varied to investigate the effects of their numbers on the ability of mesophase formation of the resultant polymers. The chemical structures of the monomers were confirmed by elemental analysis,1H NMR and13C NMR. The characterization of the polymers was performed with1H NMR, gel permeation chromatography (GPC). The phase structures and transition behaviors were studied using differential scanning calorimetry (DSC), polarized light microscopy (PLM) and one- and two-dimensional wide-angle X-ray diffraction (WAXD). The experimental results suggested that the ability of mesophase formation of the polymers decreased as the rigidity of side-chain group decreased and increased as the number of the alkoxy terminal group increased, and that all the polymers with high molecular weight showed stable columnar nematic phase (ΦN).