Compared to parts fabricated by traditional methods, 3D printed components typically show poorer mechanical strength and thereby increased potential for material damage and failure during fabrication and use. Moreover, many of the polymer material options for 3D printing are not intrinsically recyclable, requiring disposal if they suffer any damage or degradation, increasing environmental waste through the premature end of their useful life. Here, we incorporate self-healing properties towards extending the lifetimes of 3D printed polymeric objects. Inspired by biological self-healing, in which a damage event triggers an autonomic healing response, microcapsules containing healing fluids are embedded within the 3D printed composites during fabrication. These microcapsules rupture during a damage event, release the healing agent, and heal the surrounding material by polymerization, entanglement, or cross-linking. 3D printable self-healing polymer composites will increase product shelf life and improve material sustainability and long-term cost. Double shell wall polyurethane/poly (urea-formaldehyde) microcapsules are synthesized by in-situ-interfacial polymerization. Microcapsules with both solvent and monomer core fluids are prepared to investigate both solvent-healing and monomer self-healing mechanisms. Microcapsules containing healing agents are either incorporated into the host polymer matrix or are coated onto 3D printing polymer filaments to create 3D printed objects capable of self-healing. Microcapsule distribution within composites is visualized using X-ray Nano-CT imaging. Microcapsule survivability and self-healing properties of these composite materials after 3D printing are evaluated via examination of the healing efficiency and mechanical strength of the fabricated 3D printed objects. Microcapsule's impact on the polymer matrix's physical properties is investigated by mechanical characterization of 3D printed self-healing composites. Overall, these are promising approaches to the inclusion of self-healing behavior in 3D printed composites.

Breakthrough in 3D printed self-healing polymer composites

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.