Photocurable pentaerythritol triacrylate/lithium phenyl-2,4,6-trimethylbenzoylphosphinate-based ink for extrusion-based 3D printing of magneto-responsive materials

Abstract

Recent advances in additive manufacturing made it feasible to fabricate products with desired shapes and features. Herein, a new, photocurable 3D printer ink mainly based on pentaerythritol triacrylate (PETA) is reported. To achieve rapid curing needed for 3D printing process, high performance water-soluble photoinitiator, lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), was emulsified in PETA monomers and this suspension was evaluated for its polymerization kinetics by exposing to 395 nm UV-light. The distinct influences of LAP and triethanolamine (TEA) concentrations on photo-polymerization and printability were examined and an optimum concentration for extrusion-based 3D printing was found to be 10 mM and 1.62 M for LAP and TEA, respectively. Synthesized PETA-based 3D printer ink was functionalized by dispersing magnetic particles/flakes into the mixture, and consequently, a magneto responsive ink was obtained to be used in specialized applications. A ring-shaped structure embedded with micron sized iron flakes was printed as a prototype. This study presents a versatile photo-curable polymer formulation with possible translation to high performance 3D printing of customizable shapes that can be utilized in a wide range of areas such as micro-robotics and medical science.