N‐(9‐Oxo‐9H‐thioxanthen‐2‐yl) acrylamide as a Versatile Photoinitiator for Photopolymerization

Abstract

Thioxanthone (TX) and its derivatives have broad application prospects for their excellent absorption properties in the near UV range, high hydrogen scavenging capacity and ease of adjusting with LED light source. Herein, N-(9-oxo-9H-thioxanthen-2-yl)acrylamide (TXAM) was designed and synthesized as a LED-sensitive photoinitiator. TXAM exhibited a maximum absorption band matched with the LED emission spectra (e. g., 385-405 nm). Its properties were investigated via density functional theory (DFT) calculations and experiments. The results suggested that TXAM could efficiently initiate free radical polymerization as a sole-component photoinitiator upon LED irradiation; Meanwhile, a two-component system with an iodonium salt could initiate cationic polymerization and free radical/cationic hydric photopolymerization. It also could be used for deep curing system to make the interpenetrated polymer network materials.