High-Performance, Low-Cost, and Recyclable Photopolymers via Dual-Cure 3D-Printable Polyesters

Among the 3D printing technologies available for polymers, vat photopolymerization or stereolithography (SLA) is promising for future manufacturing because it uses photopolymers to print parts with incredible speed and complexity. The material properties of traditional, filament-fabricated 3D-printed parts are often inferior due to their inherent brittleness and poor interlayer bonding. Similarly, 3D-printed photopolymers are also often weaker than traditional polymers due to their structural heterogeneity. To dramatically reduce the heterogeneity, latent chemistries will be introduced into the resin that will re-organize the molecular structures to homogenize the photopolymer. This will result in photopolymers with robust properties that will enable the implementation of vat photopolymerization in mainstream manufacturing. These “dual-cure” polyesters reduce the structural heterogeneity of 3D printed photopolymers, and thus, improve material properties, decrease costs, and enable recyclability of the photopolymer. Herein, “dual-cure” refers to an initial “photo-cure” mediated by UV-light, followed by a secondary “heat-cure” where a thermal-meditated reaction takes place. This unconventional network enables a new direction of high-performing polymers for 3D printing and chemical recyclability via ester-based chemistry.