Synthesis and photopolymerization of novel UV-curable macro-photoinitiators

摘要

The design and development of macro-photoinitiators applicable to UV system has been attracted increasing attention for their excellent performance of low migration and high compatibility. Herein, four kinds of novel macro-photoinitiators (PI1-PI4) used in UV-curable coatings were synthesized by different isocyanates, 1-hydroxycyclohexyl phenyl ketone (Irgacure 184), 2-hydroxyethyl methacrylate (HEMA) and pentaerythritol triacrylate (PETA). The structures were analyzed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Moreover, the photopolymerization kinetics of the macro-photoinitiators were investigated by real-time FTIR. Results revealed that the macro-photoinitiators display higher curing efficiency, lower migration performance and better compatibility with formulation compositions compared to Irgacure 184. On the other hand, the macro-photoinitiators also served as self-initiating oligomers and had good thermal stability with 10 % weight loss temperatures (T10 %) above 299.7 degrees C. The UV-cured films consisting of oligomers and tripropylene glycol diacrylate (TPGDA) showed excellent physical properties and high curing efficiency and rapid curing rate.