Design, synthesis and thermotropic self-organization of dendronized polystyrenes with different length alkyl tails
Design, synthesis and thermotropic self-organization of dendronized polystyrenes with different length alkyl tails
复制标题
不同长度烷基尾树枝状聚苯乙烯的设计、合成及热致自组织
DOI：
10.1039/c6py01062h
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发表时间：
2016-08
影响因子：
4.6
通讯作者：
Zhang Hailiang
中科院分区：
文献类型：
--
作者：
Yang Ming;Mao Dongxiong;Chen Sheng;Zhang Hailiang
采用自由基聚合法合成了一系列不同长度的树枝状聚苯乙烯--聚{3，4，5-三烷氧基苯乙烯}（PTAVB-m，其中m为烷氧基中的碳原子数，m = 6，8，10，12，14，16，18）。单体的化学结构经1H NMR、13 C NMR和质谱确证。用1H NMR、凝胶渗透色谱和热重分析对相应的聚合物进行了分析。聚合物的相行为进行了研究，通过组合的技术，包括差示扫描量热法，偏光显微镜，温度可变的FT-IR光谱，小角X-射线散射，和1D和2D广角X-射线衍射。结果表明，对于最简单的树枝化聚合物，烷基端基的长度对相结构和相转变有显著的影响。当m = 6时，PTAVB-6为无定形聚合物。当尾长增加到8和10时，在低温下，聚合物的相是无定形的。而在高温下，聚合物的物相为主链和侧基形成的柱状晶。在随后的冷却之后，LC相消失，这表明在加热和冷却过程中形成了可重入的各向同性相。此外，当尾长增加到12（m ≥ 12）时，在进入凹入各向同性相之前，聚合物是结晶的。本工作首次在高分子量的树枝状液晶聚合物中观察到了凹入的各向同性相。这一发现对于新型液晶材料的制备和在不同领域的应用具有重要意义。
A series of dendronized polystyrenes with different length alkyl tails, poly{3,4,5-tris(alkoxy)styrene} (denoted as PTAVB-m, where m is the number of carbons in the alkoxy groups, m = 6, 8, 10, 12, 14, 16, 18), were synthesized via conventional free radical polymerization. The chemical structure of the monomers was confirmed by 1H NMR, 13C NMR and mass spectrometry. Analyses of the corresponding polymers were performed with 1H NMR, gel permeation chromatography and thermogravimetric analysis. The phase behavior of the polymers was investigated by a combination of techniques including differential scanning calorimetry, polarizing optical microscopy, temperature-variable FT-IR spectroscopy, small-angle X-ray scattering, and 1D and 2D wide-angle X-ray diffraction. The results showed that the length of the alkyl tails has significant effects on the phase structure and phase transition for the simplest dendronized polymers. When m = 6, PTAVB-6 was an amorphous polymer. When the tail length increases to 8 and 10, at low-temperature, the phase of the polymers was amorphous. However, at high-temperature, the phase of the polymers was columnar nematic formed by the main chain and side groups. Following a subsequent cooling, the LC phase disappeared, which indicated that a reentrant isotropic phase formed during the heating and cooling processes. Moreover, when the tail length was increased to 12 (m ≥ 12), prior to entering the reentrant isotropic phase, the polymers were crystalline. In this work, a reentrant isotropic phase was observed for the first time in the dendritic liquid crystalline polymers characterized by high molecular weight. This observation is of great importance for the preparation and use of a new type of liquid crystal material in different fields.
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影响因子：
5.5
作者：
Hui-lin Tu;X. Wan;Yu-xiang Liu;Xiaofang Chen;D. Zhang;Qifeng Zhou;Zhihao Shen;J. J. Ge-J.;Shi Jin-S
通讯作者：
Hui-lin Tu;X. Wan;Yu-xiang Liu;Xiaofang Chen;D. Zhang;Qifeng Zhou;Zhihao Shen;J. J. Ge-J.;Shi Jin-S
影响因子：
5.5
作者：
Liang, Dehai;Fan, Xinghe;Shen, Zhihao;Zhou, Qifeng
通讯作者：
Zhou, Qifeng
DOI：
10.1002/pola.27003
发表时间：
2014-02
期刊：
Journal of Polymer Science Part A
影响因子：
--
作者：
Yu-feng Zhu;Hai-jian Tian;Honglian Wu;De-Zhao Hao;Yu Zhou;Zhihao Shen;Dechun Zou;P. Sun;Xinghe Fan;Qifeng Zhou
通讯作者：
Yu-feng Zhu;Hai-jian Tian;Honglian Wu;De-Zhao Hao;Yu Zhou;Zhihao Shen;Dechun Zou;P. Sun;Xinghe Fan;Qifeng Zhou
DOI：
10.1002/pola.23167
发表时间：
2009-01
期刊：
Journal of Polymer Science Part A
影响因子：
--
作者：
Si Chen;Lanying Zhang;Longcheng Gao;Xiaofang Chen;Xinghe Fan;Zhihao Shen;Qifeng Zhou
通讯作者：
Si Chen;Lanying Zhang;Longcheng Gao;Xiaofang Chen;Xinghe Fan;Zhihao Shen;Qifeng Zhou
影响因子：
5.5
作者：
Yongfeng Zhao;Xinghe Fan;X. Wan;Xiaofang Chen;Yi;Liangyuan Wang;Xia Dong;Qifeng Zhou
通讯作者：
Yongfeng Zhao;Xinghe Fan;X. Wan;Xiaofang Chen;Yi;Liangyuan Wang;Xia Dong;Qifeng Zhou