Organic gels prepared from side-chain liquid crystalline polymers without the spacer
Organic gels prepared from side-chain liquid crystalline polymers without the spacer
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无间隔基侧链液晶聚合物制备的有机凝胶
DOI：
10.1002/pat.4215
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发表时间：
2018
影响因子：
3.4
通讯作者：
Hailiang Zhang
中科院分区：
文献类型：
--
作者：
Lei Chen;Yongjie Yuan;Jindi Li;Hailiang Zhang
合成了一系列不含间隔基的侧链液晶聚合物，命名为聚[ω-(4‘-烷氧基联苯-4-氧基)甲基丙烯酸酯(PMBiCm，m=1，2，4，6，8，10，12，14，16，18)。将PMBiCm引入到普通有机溶剂中，制备了新型的聚合物有机凝胶。聚合物有机凝胶剂的溶解度和凝胶性质因溶剂性质的不同而有很大差异。在芳香族溶剂中，由于联苯基团与芳香族溶剂的良好相容性，PMBiCm完全溶解在溶剂中。聚[ω-(4‘-正-烷氧基联苯-4-氧基)甲基丙烯酸酯]仍不溶于丙酮、乙醇、二甲基甲酰胺、乙二醇和正丁醇等极性溶剂。这一行为是由于PMBiCm和溶剂之间的溶解度参数不匹配造成的。考虑到溶剂的因素，我们系统地研究了3种不同极性的有机溶剂(乙酸丁酯、正丁胺和正庚烷)。结果表明，SCLCPs的烷氧基尾链长度对凝胶的凝胶性和凝胶热稳定性有显著影响。在进一步的UV-Vis光谱研究中，结果表明联苯基元的π-π堆积相互作用可能是指导自组装过程和聚合物凝胶形成的关键因素。这项工作有助于理解聚合物有机凝胶的物理机制。同时，这些也将SCLCP扩展到广泛的应用领域。
A series of side‐chain liquid crystal polymers (SCLCPs) without the spacer, named poly[ω‐(4′‐n‐alkyl oxybiphenyl‐4‐oxy)methacrylate (PMBiCm,m= 1, 2, 4, 6, 8, 10, 12, 14, 16, and 18), have been synthesized. The novel polymer organogels were prepared by introducing PMBiCm into common organic solvents. Solubility and gel properties of polymer organogelators differ widely according to the nature of the solvents. In aromatic solvents, PMBiCm completely dissolved in solvent due to good compatibility between biphenyl mesogen group and aromatic solvents. Poly[ω‐(4′‐n‐alkyl oxybiphenyl‐4‐oxy)methacrylate were still insoluble in polar solvents such as acetone, ethanol, DMF, ethylene glycol, and n‐butanol. This behavior resulted from mismatch of solubility parameter between PMBiCm and solvent. Considering the factors of solvent, we have systematically studied 3 organic solvents with different polarities (butyl acetate, n‐butyl amine, and n‐heptane). It is found that the length of the alkoxy tail chain of the SCLCPs has significant influence on gelability and gel thermal stability. In further studies discussed by UV‐Vis spectroscopy, the results revealed that the π‐π stacking interaction of the biphenyl mesogens might be the key factor for guiding the self‐assembly processes and the polymer gel formation. This work is useful to comprehending physical mechanism of polymer organogels. Meanwhile, those expand SCLCPs to a wide range of applications.