(565f) 3D-Printing of Self-Healing Polymer Composites

3D printed components typically show poor mechanical strength when compared to parts fabricated by traditional methods, leading to increased potential for material damage during fabrication and use. Additionally, many of the polymer material options for 3D printing are not intrinsically recyclable, requiring disposal if they suffer any damage or degradation which increases environmental waste through premature end of their useful life. Thus, we aim to improve the lifetimes of 3D printed polymeric objects through the incorporation of self-healing properties. Inspired by biological self-healing, in which a damage event triggers an autonomic healing response, microcapsules containing healing agents can be embedded into a host material. During a damage event these microcapsules rupture, 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 thereby 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 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.