Zeolite-Reinforced Interpenetrating Polymer Network Initiated by Chalcone Based Photoinitiating System and Their Application in 3D/4D Printing

With the rapid development of photopolymerization, the search for new near-UV/visible light sensitive photoinitiating system (PIS) is one of the most interesting topics in polymerization area. In this work, a new PIS (chalcone dye/amine/iodonium salt) could efficiently and simultaneously initiate the free radical photopolymerization of polyethylene glycol diacrylate (PEGDA) and the cationic photopolymerization (CP) of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (EPOX) upon LED@405 nm irradiation to obtain interpenetrating polymer network (IPN). Furthermore, this PIS was employed in the photopolymerization of LTA-5A zeolite filled interpenetrating polymer network composites (IPN, PEGDA/EPOX). Compared to the pure IPN, the depth of cure (DOC) for IPN with 50 wt% LTA-5A remarkably increased by ca. 90%, which was the first time reported that DOC could increase with the increase of the filler content. 3D patterns with good resolution were manufactured through direct laser write technique, and those with high filler contents showed good water swelling property. Under hydrothermal stimuli, IPN composite with 50 wt% LTA-5A exhibited a good 4D printing behavior. Therefore, not only this chalcone dye has a good photoinitiation ability for photopolymerization, but also the resulting IPN composites prepared with the photoinitiating system containing this dye have potential applications for 3D/4D printing and composites preparation.

Automated summary

In this study, a new photoinitiating system was developed for efficient free radical photopolymerization and cationic photopolymerization, resulting in an interpenetrating polymer network. The use of this system in zeolite-filled photopolymer materials significantly increased the depth of cure. 3D patterns with high-resolution and good water swelling property were successfully produced using direct laser write technique. Under hydrothermal stimuli, the photopolymer material with zeolite filler displayed excellent 4D printing behavior. Therefore, this photoinitiating system has potential applications in 3D/4D printing and composite material preparation.