主链环状偶氮苯聚合物的首个实例。

The first example of main-chain cyclic azobenzene polymers.

作者信息

Xu Xu, Zhou Nianchen, Zhu Jian, Tu Yingfeng, Zhang Zhengbiao, Cheng Zhenping, Zhu Xiulin

机构信息

Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science of Soochow University, Suzhou 215123, P. R. China.

出版信息

Macromol Rapid Commun. 2010 Oct 18;31(20):1791-7. doi: 10.1002/marc.201000218.

DOI:10.1002/marc.201000218

PMID:21567595

Abstract

A novel main-chain azobenzene cyclic polymer, cyclic-PEHPA, has been successfully synthesized by 'click' cyclization of the α-alkyne-ω-azido hetero-difunctional linear precursors (linear-PEHPA), which is synthesized by a step-growth polymerization of the 3'-ethynylphenyl[4-hexyl-(2-azido-2-methyl- propionate) phenyl] azobenzene (EHPA). Gel permeation chromatography, and (1) H NMR and FT-IR spectra confirmed the complete transformation of linear-PEHPA into cyclic-PEHPA. With the same molecular weights, the cyclic-PEHPAs are found to have higher glass transition temperatures than the linear-PEHPAs, but almost the same decomposition temperatures. In addition, the obtained cyclic azobenzene polymer with lower molar mass shows a slightly better trans-cis-trans photoisomerization ability than the corresponding linear-PEHPA.

摘要

一种新型的主链偶氮苯环状聚合物，即环状-PEHPA，已通过α-炔基-ω-叠氮基杂双功能线性前体（线性-PEHPA）的“点击”环化反应成功合成，而线性-PEHPA是由3'-乙炔基苯基[4-己基-(2-叠氮基-2-甲基-丙酸酯)苯基]偶氮苯（EHPA）通过逐步增长聚合反应合成的。凝胶渗透色谱法、¹H NMR和FT-IR光谱证实了线性-PEHPA完全转化为环状-PEHPA。在分子量相同的情况下，发现环状-PEHPA的玻璃化转变温度高于线性-PEHPA，但分解温度几乎相同。此外，所获得的较低摩尔质量的环状偶氮苯聚合物的反-顺-反光异构化能力略优于相应的线性-PEHPA。