One-pot synthesis of PCL-based acrylate photoink for 3D printing

Abstract The increasing use of desktop 3D printers has driven interest in sustainable and environmentally friendly materials for additive manufacturing. This study presents a novel, biodegradable, and thermally stable photoink based on polycaprolactone urethane acrylate (PCLA). PCLA was synthesized via a one-pot, solvent-free method through the nucleophilic addition of PCL-diol and 2-isocyanatoethyl methacrylate. The resulting material was characterized by ATR-FT-IR and 1 H NMR spectroscopy, confirming the successful incorporation of urethane and acrylate functionalities into the polymer structure. Thermal analysis revealed the stability of the printed material up to 305 °C, with no significant melting or crystallization transitions, which is indicative of its flexibility and heat resistance. Mechanical testing revealed that post-UV curing and heat treatment significantly improved the consistency of the ultimate stress (2.25 MPa) and strain (21%), which is essential for reliable 3D-printing performance. The flexibility of PCLA-based prints enhances robustness and impact resistance, offering a sustainable alternative to conventional acrylates that are often brittle. Furthermore, a printed conical spring exhibited excellent compressibility and recovery without damage, highlighting the material’s potential for applications in flexible electronics and adaptable 3D structures. This study underscores the promise of PCLA-based photoinks as viable candidates for sustainable and high-performance 3D-printing applications. Graphical abstract