Epoxy-based polymers functionalized with bisazo chromophores: Synthesis, characterization and photoresponsive behavior
Epoxy-based polymers functionalized with bisazo chromophores: Synthesis, characterization and photoresponsive behavior
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DOI：
10.1016/j.polymer.2011.05.040
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发表时间：
2011-07
期刊：
影响因子：
4.6
通讯作者：
Xiao-lin Wang;Jianjun Yin;Xiaogong Wang
中科院分区：
文献类型：
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作者：
Xiao-lin Wang;Jianjun Yin;Xiaogong Wang
本文以两种前体聚合物（BP-AN和BP 35-AN）为原料，通过后聚合偶氮偶联反应合成了两个系列的含双偶氮生色团的环氧基聚合物。制备了含有不同吸电子基团和不同甲基取代基数目的双偶氮发色团的聚合物，并用1H NMR、FT-IR、GPC、UV-vis和热分析对其进行了表征。通过用三种不同波长（488、532和589 nm）的激光照射聚合物的旋涂膜，研究了聚合物的光致双折射和表面浮雕光栅（SRG）的形成。结果表明，含双偶氮发色团的聚合物与普通含偶氮苯的聚合物相比，具有较宽的吸收带，且吸收带发生红移。双偶氮发色团上的吸电子基团对吸收带位置有显著影响。光致双折射和表面浮雕光栅（SRG）的形成与生色团结构和激光激发波长密切相关。双偶氮生色团上的吸电子基团和甲基取代基对光致双折射增长速率和SRG形成速率都有明显的影响。适当的甲基取代的双偶氮生色团显示能力，提高光致双折射增长率，双折射饱和水平，和SRG形成速率。在本研究中获得的双偶氮聚合物可以进一步探索在电信，数据存储，传感器和其他光学器件中的应用。
In this work, two series of epoxy-based polymers bearing bisazo chromophores were synthesized from two precursor polymers (BP-AN and BP35-AN) through post-polymerization azo-coupling reactions. The polymers were prepared to contain bisazo chromophores with different electron-withdrawing groups and different numbers of methyl substituents, which were characterized by1H NMR, FT-IR, GPC, UV–vis, and thermal analysis. The photoinduced birefringence and surface-relief-grating (SRG) formation of the polymers were studied by irradiating spin-coated films of the polymers with laser light at three different wavelengths (488, 532, and 589 nm). The results show that the polymers containing bisazo chromophores possess broader and red-shifted absorption bands compared with ordinary azobenzene-containing polymers. The electron-withdrawing groups on the bisazo chromophores show significant effect on the absorption band positions. The behavior of photoinduced birefringence and surface-relief-grating (SRG) formation is closely correlated with the chromophore structures and excitation wavelength of the laser light. Both electron-withdrawing groups and methyl substituents on the bisazo chromophores show obvious influences on the photoinduced birefringence growth rate and SRG formation rate. The proper methyl substitution on the bisazo chromophores shows ability to enhance the photoinduced birefringence growth rate, birefringence saturation level, and SRG formation rate. The bisazo polymers obtained in this study can be further explored for applications in telecommunication, data-storage, sensors, and other optical devices.