4D Printing of Dicyclopentadiene/BaTiO₃ Polymer Composites

Dicyclopentadiene<b> </b>(DCPD) is a thermosetting polymer capable of spontaneous frontal ring-opening metathesis polymerization (FROMP) by the thermal initiation of local sites. As such, DCPD can be printed into a free-standing structure without supports, which is not possible with a conventional fused deposition moulding printer. In addition, cyclooctane can be incorporated into DCPD during FROMP to develop new smart materials with shape memory performance. In the meantime, BaTiO₃ is one of piezoelectric ceramics with excellent dielectric and piezoelectric properties, being a promising material for piezoceramic devices. Due to its poor formability and brittles, BaTiO₃ is used as a filler for polymer composites. In this research, a piezoceramic composite was prepared using DCPD and BaTiO₃ and printed into a free-standing structure without supports. For this, BaTiO₃ nanoparticles were dispersed uniformly in DCPD solution, which was confirmed using SEM and EDS analysis. Then, optimal 3D printing condition of the composite solution was explored. Lastly, the shape memory performance and the dielectric constant of the printed composite were measured to investigate the possibility of a piezoelectric ceramic device.