RECENT ADVANCES IN UV-CURING CHEMISTRY

The efficiency of newly developed photoinitiators and acrylic monomers has been evaluated in UV-curable resins by using real-time spectrosco py techniques. The kinetic profiles of these ultrafast photopolymeriza tions have been directly recorded by following either the monomer disa ppearance by infrared spectroscopy, or the photoinitiator loss by ultr aviolet spectroscopy. The best performance was obtained with formulati ons based on a morpholino-type photoinitiator and on cyclic-carbonate monoacrylates. One of the great advantages of these new monomers lies in their high reactivity, which leads to fast and extensive cure upon exposure to UV-radiation or laser beams. Chain transfer reactions play an important role in the formation of such strongly crosslinked polym ers, which exhibit remarkable mechanical properties, such as hardness, scratch resistance, flexibility, and impact resistance.