This review paper focuses on sustainable materials for vat photopolymerization (VPP) based 3D printing. Recent developments in VPP 3D printable polymers with dynamic covalent bonds are summarized, showcasing their chemical recyclability, thermo-mechanical recyclability, self-healing capabilities, and chemical degradability. Various dynamic covalent reactions and processes have been utilized, demonstrating adaptability in design and application.

Abstract

Vat photopolymerization (VPP) based three-dimensional (3D) printing, including stereolithography (SLA) and digital light projection (DLP), is known for producing intricate, high-precision prototypes with superior mechanical properties. However, the challenge lies in the non-recyclability of covalently crosslinked thermosets used in these printing processes, limiting the sustainable utilization of printed prototypes. This review paper examines the recently explored avenue of VPP 3D-printed dynamic covalent network (DCN) polymers, which enable reversible crosslinks and allow for the reprocessing of printed prototypes, promoting sustainability. These reversible crosslinks facilitate the rearrangement of crosslinked polymers, providing printed polymers with chemical/physical recyclability, self-healing capabilities, and degradability. While various mechanisms for DCN polymer systems are explored, this paper focuses solely on photocurable polymers to highlight their potential to revolutionize the sustainability of VPP 3D printing.