From Regioirregular Linear Main-Chain Liquid-Crystal Polyethers Exhibiting Two Uniaxial Nematic Phases to Macrocyclic Main-Chain Oligoethers Displaying Nematic and Smectic Phases
From Regioirregular Linear Main-Chain Liquid-Crystal Polyethers Exhibiting Two Uniaxial Nematic Phases to Macrocyclic Main-Chain Oligoethers Displaying Nematic and Smectic Phases
复制标题
从表现出两个单轴向列相的区域不规则线性主链液晶聚醚到表现出向列相和近晶相的大环主链低聚醚
DOI：
10.1021/cm9602048
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发表时间：
1996
影响因子：
8.6
通讯作者：
G. Ungar
中科院分区：
文献类型：
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作者：
V. Percec;A. D. Asandei;G. Ungar
基于构象柔性1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane(MBPE)和α，ω-二溴代烷的区域不规则大环化合物的合成和表征，即mBPE-(C)X(Z)(其中c代表环，X=4，5，9，11表示柔性间隔基中的亚甲基数目，z=1，−5是大环的齐聚程度)，并将它们与相应的高分子量线性聚合物MBPE-(L)X的相行为进行比较(其中L表示线性，X的含义与环的情况相同)。讨论了X和z对MBPE-(C)X(Z)相行为的影响。对于适当的(X，z)对，如(4，5)，(5，4)，(9，3)，(9，4)，(11，3)和(11，4)，MBPE-(C)X(Z)比相应的线性聚合物具有更强的产生和稳定液晶(LC)相的能力。具有X=奇数的MBPE-(L)X呈现两个单轴向列相。MBPE-(C)X(Z)不显示第二单轴NEMA...
The synthesis and characterization of regioirregular macrocyclics based on the conformationally flexible 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane (MBPE) and α,ω-dibromoalkanes, i.e., MBPE-(c)X(z) (where c stands for cyclic, X = 4, 5, 9, and 11 represents the number of methylenic groups in the flexible spacer and z = 1−5 is the degree of oligomerization of the macrocyclic) and the comparison of their phase behavior with that of the corresponding high molecular weight linear polymers MBPE-(l)X (where l stands for linear and X has the same meaning as in the case of cyclics) are described. The effects of X and z on the phase behavior of MBPE-(c)X(z) is discussed. For proper (X, z) pairs such as (4, 5), (5, 4), (9, 3), (9, 4), (11, 3), and (11, 4), MBPE-(c)X(z) have a higher ability to generate and stabilize liquid-crystalline (LC) phases than the corresponding linear polymers. MBPE-(l)X with X = odd numbers exhibit two uniaxial nematic phases. MBPE-(c)X(z) do not display the second uniaxial nema...