Stereolithographic 3D Printing of Intrinsically Flame‐Retardant Shape‐Memory Polymers

This study presents a novel approach to fabricate 3D‐printed phosphorous‐based acrylate monomers using stereolithographic 3D printing technology, aiming to create demonstrators with exceptional shape‐memory characteristics and robust flame retardant properties. The synthesized materials combine the advantages of 3D printing precision with the intrinsic flame retardancy of phosphorous‐based monomers, offering a versatile solution for applications requiring both shape memory functionality and fire resistance. The limiting oxygen index (LOI) value of the intrinsically flame‐retardant shape‐memory polymer (IFR‐SMP) can reach 34%, and the vertical combustion rating after UL 94 can obtain V‐0. The mechanism of the IFR‐SMP flame retardant mainly includes terminating a free‐radical chain reaction and gas phase dilution, which indicates that the gas‐phase mechanism plays an important role in the flame retardancy. This work advances the frontiers of 3D printing technology by demonstrating the synergistic potential of shape memory and flame retardancy within a single material system, providing a pathway toward the development of innovative and resilient materials for the future.