Photopolymerization properties of Type II photoinitiator based on Thioxanthone hydrogen acceptor and various amine-type hydrogen donors

• Main Authors: Ting-Yu Liu, 劉廷昱
• Other Authors: Yung-Chung Chen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/ay6sy4

碩士 === 國立高雄科技大學 === 化學工程與材料工程系 === 107 === In this work, we investigated the double bonds conversion efficiencies (DC values) based on different Type II photoinitiator packages through gel fraction method. The formulations are including a trifunctional monomer of trimethylolpropane trimethacrylate (TMPTMA), hydrogen acceptor of Thioxathone (TX) and five amine-type hydrogen donors N-Phenylglycine (NPG), Triethylamine (TEA), Triethanolamine (TEOA), 2,2'-(4-Methylphenylimino)diethanol (p-TDEA), N-Phenyldiethanolamine (n-PDEA), respectively. Among those formulations, the TX/TEOA photoinitiator package showed the best DC values than others. The DC values are in the order of 1:2 wt% > 1.5:1.5wt% > 2:1 wt% for weight ratios investigation of TX/TEOA PI packages. In addition, the DC values are insignificant in either air or nitrogen under TX/TEOA at 1:2 wt%. We also investigated their photochemical and photophysical properties. The hydrogen donors exhibited the absorption band at lower than 300 nm, which followed the trend p-TDEA > n-PDEA > NPG > TEOA > TEA. After mixing TX with various amine-type hydrogen donors, the PL intensity increased in the following order: TX/p-TDEA > TX/n-PDEA > TX/ NPG > TX/TEA > TX/TEOA. Based on the results of photochemical analysis, the measured molar extinction coefficient was TEA> TEOA> p-TDEA> n-PDEA> NPG. Though all the Type II series exhibited good electron transfer ability by cyclic voltammetry (CV) and free energy change ΔGET results. However, steric hindrance and secondary and tertiary of the amines hydrogen donors played the major factor on the rate of photopolymerization.