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首页> 外文期刊>Chemistry: A European journal >Click-dendronized poly(amide-triazole)s-effect of dendron size and polymer backbone symmetry on self-assembling and gelation properties
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Click-dendronized poly(amide-triazole)s-effect of dendron size and polymer backbone symmetry on self-assembling and gelation properties

机译：点击-树枝化的聚（酰胺-三唑）-树突大小和聚合物骨架对称性对自组装和胶凝性能的影响

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Nine dendronized poly(amide-triazole)s 2-Gm Gn (m=1-3, n=1-3), were prepared by the 1:1 copolymerization between AA-type dendritic diazides 4-Gm (m=1-3) and BB-type dendritic diacetylenes 5-Gn (n=1-3) under the copper(I)-mediated click coupling conditions. The degree of polymerization value of the polymers was found to range from 15-50, and decreased with increasing size of the dendron, suggesting steric hindrance had a retardation role on the copolymerization efficiency. Based on FT-IR and 1HNMR studies, it was found that significantly strong, interchain hydrogen bonding between the amide units was present in the solution state after copolymerization, whereas the monomers 4-Gm and 5-Gn were devoid of any intermolecular hydrogen-bonding interaction. Hence a positive allosteric hydrogen-bonding effect was observed after polymerization, and could be rationalized by the zip effect. The strength of the interchain association in polymers 2-Gm Gn was found to decrease with increasing size of the dendron (i.e., 2-G1 G1>2-G1 G2>2-G2 G1≈2-G2 G2>2-G1 G3≈2-G3 G1>2-G2 G3≈2-G3 G2>2-G3 G3). Among the nine polymers, only 2-G1 G2 and 2-G2 G1 were good organogelators for aromatic solvents, while the 2-G2 G2 polymer, bearing the closest structural resemblance to the previously reported organogelator 1-G2 prepared from the polymerization of AB-type monomers, was devoid of gelating power. Careful analysis of structures of the present polymer series 2-Gm Gn and the previously reported series 1-Gn suggested that the polymer backbone symmetry played a subtle role in controlling their self-assembling and gelating properties. Antiparallel versus parallel arrangements of polymer repeating unit dipoles: In a dendronized poly(amide-triazole), both the size of the dendritic appendage as well as the relative alignment of the dipole of the repeating unit along the polymer backbone can have a significant influence on its self-assembling and gelation properties. Hence, the top dendronized polymer shown is a very good organogelator, while the bottom is nongelating.
机译：通过AA型树枝状叠氮化物4-Gm（m = 1-3）之间的1：1共聚制备九个树枝状的聚（酰胺-三唑）s 2-Gm Gn（m = 1-3，n = 1-3） ）和BB型树枝状联乙炔5-Gn（n = 1-3）在铜（I）介导的点击偶联条件下。发现该聚合物的聚合度值在15-50的范围内，并且随着树枝状分子尺寸的增加而降低，表明空间位阻对共聚效率具有延迟作用。根据FT-IR和1HNMR研究，发现共聚后，酰胺单元之间的溶液状态下存在明显强的链间氢键，而单体4-Gm和5-Gn没有分子间氢键相互作用。因此，聚合后观察到正的变构氢键合效应，并且可以通过拉链效应使其合理化。发现聚合物2-Gm Gn中链间缔合的强度随树枝状分子尺寸的增加而降低（即2-G1 G1> 2-G1 G2> 2-G2G1≈2-G2G2> 2-G1G3≈ 2-G3 G1> 2-G2G3≈2-G3G2> 2-G3 G3）。在这九种聚合物中，只有2-G1 G2和2-G2 G1是芳族溶剂的良好有机胶凝剂，而2-G2 G2聚合物与先前报道的由AB-聚合制备的有机胶凝剂1-G2具有最相似的结构相似性。型单体，没有胶凝能力。仔细分析本聚合物2-Gm Gn系列和先前报道的1-Gn系列聚合物表明，聚合物骨架对称性在控制其自组装和胶凝性能方面起着微妙的作用。聚合物重复单元偶极子的反平行与平行排列：在树枝状聚（酰胺-三唑）中，树枝状附肢的大小以及沿着聚合物主链的重复单元偶极子的相对排列都可能对它的自组装和胶凝特性。因此，所示的顶部树状聚合物是非常好的有机胶凝剂，而底部是非胶凝剂。

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