Photo-assisted ultrasonic curing for ultrafast and deep prototyping based on coumarin derivatives

Abstract

Although photocuring is currently the most commonly used method in 3D additive manufacturing, it still faces significant challenges in rapid prototyping of thick materials due to the limited penetration of light. Ultrasonic technology has the advantages of high penetration depth and unparalleled cavitation, offering opportunities for enabling additive manufacturing of thick materials. In this study, a coumarin-based two-component system composed of Coum-Ph-OC12H25 and N-phenylglycine as initiator and hydrogen supplier, respectively, was developed to achieve ultrasonic curing of tripropylene glycol diacrylate (TPGDA). The ideal curing efficiency of this two-component system was optimized to 90 %, and ultrasonic curing of thick materials was achieved with a penetration depth of up to 15 cm. Moreover, electron spin resonance (ESR) spectroscopic measurements demonstrated the free-radical reaction mechanism. It is believed that this research has the potential to expand the 3D additive manufacturing technology and pave the way for future developments in this field.