Institute of Science and Materials of Mulhouse IS2M-UMR, The National Center for Scientific Research (CNRS) 7361-UHA, 15, Rue Jean Starcky, 68057 Mulhouse CEDEX, France.
Laboratory of Materials, Catalysts, Environment and Analytical Methods (MCEMA-CHAMSI), EDST, Lebanese University, Campus Hariri, Hadath, Beyrouth, Lebanon.
Molecules. 2017 Dec 4;22(12):2143. doi: 10.3390/molecules22122143.
Radical chemistry is a very convenient way to produce polymer materials. Here, an application of a particular photoinduced radical chemistry is illustrated. Seven new carbazole derivatives - are incorporated and proposed as high performance near-UV photoinitiators for both the free radical polymerization (FRP) of (meth)acrylates and the cationic polymerization (CP) of epoxides utilizing Light Emitting Diodes LEDs @405 nm. Excellent polymerization-initiating abilities are found and high final reactive function conversions are obtained. Interestingly, these new derivatives display much better near-UV polymerization-initiating abilities compared to a reference UV absorbing carbazole (CARET 9-carbazole-9-ethanol) demonstrating that the new substituents have good ability to red shift the absorption of the proposed photoinitiators. All the more strikingly, in combination with iodonium salt, - are likewise preferred as cationic photoinitiators over the notable photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BAPO) for mild irradiation conditions featuring their remarkable reactivity. In particular their utilization in the preparation of new cationic resins for LED projector 3D printing is envisioned. A full picture of the included photochemical mechanisms is given.
自由基化学是一种非常方便的生产聚合物材料的方法。在这里，我们展示了一种特定的光诱导自由基化学的应用。我们将 7 种新型咔唑衍生物 - 设计并提出作为高效近紫外光引发剂，用于（甲基）丙烯酸酯的自由基聚合（FRP）和环氧化合物的阳离子聚合（CP），利用发光二极管（LED）在 405nm 下进行光引发。我们发现这些新衍生物具有出色的聚合引发能力，并获得了高的最终反应官能团转化率。有趣的是，与参考的紫外吸收咔唑（CARET 9-咔唑-9-乙醇）相比，这些新的衍生物显示出更好的近紫外光聚合引发能力，这表明新的取代基具有良好的吸收红移能力。更引人注目的是，与碘鎓盐结合，- 也被优选作为阳离子光引发剂，而不是著名的光引发剂双（2,4,6-三甲基苯甲酰基）苯基氧化膦（BAPO），用于温和的辐照条件，具有显著的反应性。特别地，它们被设想用于制备用于 LED 投影仪 3D 打印的新型阳离子树脂。给出了所包含的光化学机制的全貌。
