Journal of Coatings Technology and Research ( IF 2.3 ) Pub Date : 2020-09-29 , DOI: 10.1007/s11998-020-00401-9 Yung-Chung Chen , Ting-Yu Liu , Yan-Heng Li
In this work, free radical photopolymerization of trimethylolpropane trimethacrylate (TMPTMA) is initiated. We investigated the corresponding photoreactivity by using Type II photoinitiator (PI) systems based on thioxanthone (TX) as a hydrogen acceptor and five amine-type molecules, such as N-phenylglycine (NPG), triethylamine (TEA), triethanolamine (TEOA), 2,2′-(4-methylphenylimino)diethanol (p-TDEA), and N-phenyldiethanolamine (n-PDEA), as hydrogen donors. Their photochemical and photophysical properties are studied. The TX hydrogen acceptor displayed rather red-shifted compared to all the hydrogen donor compounds. The hydrogen donor compounds exhibited the absorption band at lower than 300 nm, which followed the trend of p-TDEA > n-PDEA > NPG > TEOA > TEA. All the packages exhibit good electron-transfer ability by the calculation of the free energy changes (ΔGET) through cyclic voltammetry (CV) measurement. However, the hydrogen donors with different steric hindrance, secondary, and tertiary amines have a decisive influence on the photoreactivity; that is, the TX/TEOA package shows the best double-bond conversion (DC) efficiency than other formulations under similar weight ratios (hydrogen acceptor: hydrogen donor = 1:2 wt%). We then conduct the photoreactivity based on TX/TEOA formulation with different weight ratios. The DC values are in the order of 1:2 wt% > 1.5:1.5 wt% > 2:1 wt%. Under suitable amount of hydrogen donor, the TX/TEOA-based formulation also exhibits stable DC value at air atmosphere.
中文翻译:
使用包含噻吨酮引发剂作为氢受体和多种胺类共引发剂作为氢供体的II型光引发剂进行光引发自由基聚合的光反应性研究
在这项工作中,引发了三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)的自由基光聚合。我们通过使用基于噻吨酮(TX)作为氢受体和5种胺类分子的II型光引发剂(PI)系统研究了相应的光反应性,例如N-苯基甘氨酸(NPG),三乙胺(TEA),三乙醇胺(TEOA), 2,2'-(4-甲基苯基亚氨基)二乙醇(p -TDEA)和N-苯基二乙醇胺(n -PDEA)作为氢供体。研究了它们的光化学和光物理性质。与所有氢供体化合物相比,TX氢受体显示出相当红移。氢供体化合物在低于300 nm处表现出吸收带,这遵循了p -TDEA> n -PDEA> NPG> TEOA> TEA。通过计算自由能变化(ΔG ET)通过循环伏安法(CV)进行测量。但是,具有不同位阻,仲胺和叔胺的氢供体对光反应性具有决定性的影响。也就是说,在类似的重量比(氢受体:氢供体= 1:2重量%)下,TX / TEOA封装显示出比其他配方最佳的双键转化(DC)效率。然后,我们基于不同重量比的TX / TEOA配方进行光反应性。DC值的顺序为1∶2重量%> 1.5∶1.5重量%> 2∶1重量%。在适量的氢供体下,基于TX / TEOA的配方在空气中也表现出稳定的DC值。