A new photo-crosslinkable second-order nonlinear optical (NLO) linear polymer was designed and successfully prepared by the azido-alkyne click reaction, in which the azo-benzene moieties acted as the chromophore. The latent double bonds in the polymer could undergo the subsequent thiol–ene click reaction with the addition of pentaerythritol tetra(3-mercaptopropionate)(PETMP) as the controlled photo-crosslinking, with the aid of UV lamp irradiation. Accordingly, the photo-crosslinked thin films exhibited much enhanced stability of the macroscopic second-order NLO effect. Thanks to the advantages of the azido-alkyne and thiol–ene click reactions, the syntheses were very simple and the post crosslinking process was convenient. Under the optimized conditions, the T_80% of the photo-crosslinked thin films (103 °C) was much higher than that of the controlled ones (57 °C), thus opening up a new avenue for the improvement of device stability.

中文翻译：

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可光交联的二阶非线性光学聚合物：易于合成和增强的NLO热稳定性†

设计了一种新型的可光交联的二阶非线性光学（NLO）线性聚合物，并通过叠氮基-炔烃点击反应成功制备，其中偶氮-苯部分作为生色团。聚合物中潜在的双键可随后通过添加季戊四醇四（3-巯基丙酸酯）（PETMP）作为受控的光交联而发生硫醇-烯点击反应，借助于紫外线灯照射。因此，光交联的薄膜表现出宏观的二级NLO效应的稳定性大大提高。由于叠氮基炔和硫醇-烯点击反应的优势，合成非常简单，后交联过程也很方便。在优化条件下，T _80％ 光交联薄膜（103°C）的薄膜比受控薄膜（57°C）的薄膜高得多，从而为提高器件稳定性开辟了一条新途径。