Semicrystalline poly(vinyl ether)s with high and phototunable glass transition temperature: application for thermally stable and reworkable adhesives
Semicrystalline poly(vinyl ether)s with high and phototunable glass transition temperature: application for thermally stable and reworkable adhesives
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DOI：
10.1002/pol.20190153
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发表时间：
2020-02-15
影响因子：
3.4
通讯作者：
Kihara, Hideyuki
中科院分区：
文献类型：
--
作者：
Ito, Shotaro;Akiyama, Haruhisa;Kihara, Hideyuki
偶氮苯类聚合物的光致固-液相变是一种合成具有刺激响应性功能材料的有效方法。由于这些材料的结构与性能的关系还没有完全了解，一类新的聚合物主链，即聚（乙烯基醚）（PVE），进行了研究，用于开发偶氮苯基聚合物具有高的热稳定性。为此，采用刘易斯酸催化的阳离子聚合方法合成了一系列具有不同单体结构的偶氮苯系PVE。典型的PVE是具有低玻璃化转变温度（T-g）的粘性聚合物。聚合物主链的柔性随着亚烷基间隔基的使用而改善，改变了连接到主链的介晶偶氮苯部分的排列顺序，导致基于偶氮苯的PVE的高T-g。其中一种合成的PVE显示出94摄氏度的高玻璃化转变温度，与相应的聚甲基丙烯酸酯相比高出14摄氏度。此外，PVE表现出光诱导的固-液相变从半结晶状态。这种相变材料具有较高的热稳定性，具有更广泛的应用潜力，例如用于粘附的光调谐。(c)2020 Wiley Periodicals，Inc. J.波利姆Sci. 2020，58，568-577
The photoinduced solid-liquid phase transition of azobenzene-based polymers is an attractive method to synthesize stimuli-responsive functional materials. As the structure-property relationships of such materials are not fully understood, a new class of polymer backbone, that is, poly(vinyl ether) (PVE), was studied for the development of azobenzene-based polymers with high thermal stability. For this purpose, a series of azobenzene-based PVEs with different monomer structures were synthesized using a Lewis acid catalyst-based cationic polymerization method. Typical PVEs are viscous polymers with low glass-transition temperatures (T-g's). The flexibility of the polymer backbone improves with the use of alkylene spacers, changing the order of alignment of the mesogenic azobenzene moieties attached to the backbone, leading to high T-g's of the azobenzene-based PVEs. One of the synthesized PVEs shows a high glass-transition temperature of 94 degrees C, which is 14 degrees C higher compared to that of the corresponding polymethacrylate. Furthermore, the PVE exhibits photoinduced solid-liquid phase transition from the semicrystalline state. This phase transition material, with its high thermal stability, has the potential for broader applications, such as for the phototuning of adhesion. (c) 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 568-577