Konieczkowska Jolanta, Neugebauer Dorota, Kozanecka-Szmigiel Anna, Mazur Aleksy, Kotowicz Sonia, Schab-Balcerzak Ewa
Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 34 M. Curie-Sklodowska Str., 41-819, Zabrze, Poland.
Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, Ks. Marcina Strzody 9, 44-100, Gliwice, Poland.
Sci Rep. 2024 Apr 20;14(1):9078. doi: 10.1038/s41598-024-59704-1.
A new azo polymer containing photoisomerizable azo pyridine functionalities was synthesized via Mitsunobu reaction of 4-(4-hydroxyphenylazo)pyridine with poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) for creating new photochromic materials. The resulting polymer with azo pyridine side groups was characterized for structural, thermal, and optical properties. UV-vis, H NMR and IR spectroscopies confirmed that all hydroxyl groups in p(HEMA-co-MMA) were substituted with azo dye. The obtained azo copolymer exhibited high thermal stability (around 240 °C) and a glass transition temperature (113 °C), promising for applications. The trans-to-cis isomerization upon UV irradiation and the thermal back reaction of the azo chromophore in the copolymer in the solid state was studied. A photostationary state with 50% content of cis-isomers upon 6 min of UV irradiation was reached, and during 48 h dark relaxation at ambient temperature, all cis-isomers converted to the trans form. Additionally, the possibility of efficient photogeneration of surface relief gratings with high amplitude of azo copolymer surface modulation was demonstrated.
通过4-(4-羟基苯基偶氮)吡啶与聚(甲基丙烯酸2-羟乙酯-共-甲基丙烯酸甲酯)(p(HEMA-co-MMA))的 Mitsunobu 反应合成了一种含有可光异构化偶氮吡啶官能团的新型偶氮聚合物，用于制备新型光致变色材料。对所得带有偶氮吡啶侧基的聚合物进行了结构、热性能和光学性能表征。紫外可见光谱、核磁共振氢谱和红外光谱证实p(HEMA-co-MMA)中的所有羟基均被偶氮染料取代。所得到的偶氮共聚物表现出高的热稳定性(约240℃)和玻璃化转变温度(113℃)，具有应用前景。研究了共聚物在固态下偶氮发色团在紫外光照射下的反式-顺式异构化以及热逆向反应。在紫外光照射6分钟后达到了顺式异构体含量为50%的光稳态，并且在室温下48小时的暗弛豫过程中，所有顺式异构体都转化为反式形式。此外，还证明了利用偶氮共聚物表面调制的高幅度有效光生表面浮雕光栅的可能性。
