Synthesis and Characterization of a New Functional Photoinitiator for the Curing of Biocompatible Polymer Materials

In UV curing technology, traditional photoinitiators are widely used in fields such as food packaging and medical devices, but they have some issues. These include migration, volatility and toxicity of the residue photoinitiator during their useful periods. This study aims to develop specialized photoinitiators specifically for food packaging and medical devices to address this gap. A novel photoinitiator, 2-{2-[4-(2-hydroxy-2-methylpropan-oyl) phenoxy]ethoxy}ethyl 2-acetoxybenzoate (AI-2959), was synthesized via esterification between acetylsalicylic acid (aspirin) and the commercial photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2- methyl- propiophenone (I-2959). The structure was confirmed using Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (¹H NMR), and elemental analysis, and the physicochemical properties of AI-2959 and I-2959 were compared. The ultraviolet spectra revealed absorption characteristics similar to I-2959 but with a higher molar extinction coefficient, indicating superior photosensitivity. Thermogravimetric analysis demonstrated improved thermal stability, and photopolymerization kinetics studies showed enhanced resistance to oxygen inhibition and higher double-bond conversion. Coating performance tests indicated a shorter curing time, greater hardness, and excellent adhesion. Importantly, the relative migration rate of AI-2959 was only 10.2% of that of I-2959, significantly reducing potential biotoxicity risks. These properties suggest the good potential of AI-2959 for use in biomedical and pharmaceutical applications involving UV curing.