Enhancing vitrimer applications: development of E-GMA/EMAZn vitrimeric filaments for advanced 3D/4D printing

Abstract Vitrimers represent a promising class of polymers that combine the reprocessability of thermoplastics with the stability of thermosets due to their dynamic covalent networks. However, the fabrication of vitrimer filaments suitable for additive manufacturing remains a significant challenge, limiting their widespread adoption. In this study, a vitrimer filament was successfully developed using an epoxidized ethylene-glycidyl methacrylate copolymer and a zinc ionomer. The filament was extruded at 150 °C to minimize premature cross-linking, maintaining a low gel content (∼20%) to ensure proper flowability during 3D printing. The optimized printing conditions (190 °C, 30 mm s −1 ) enabled the fabrication of complex structures while preserving processability. Post-curing at 150 °C for 60 min led to a cross-linked vitrimer network, as confirmed by gel content analysis, which increased from approximately 48% after printing to approximately 80% after curing. The printed vitrimer exhibited excellent mechanical stability, with stress–strain curves showing negligible differences between the original and recycled samples, highlighting its reprocessability. Furthermore, 4D printing capabilities were demonstrated through a shape memory experiment, where specimens programmed at 90 °C achieved close to 100% fixation and 100% recovery in a water bath. The plasticizing effect of water facilitated segmental mobility, enhancing recovery compared to dry conditions. This study not only advances the scalable production of vitrimer filaments but also establishes their potential for functional applications in self-healing, adaptive structures, and recyclable printed components. The combination of tunable mechanical properties, processability, and shape memory behavior positions this vitrimer system as a viable candidate for next-generation smart materials in additive manufacturing.