title: Effect of 3D-Printed Microvascular Network Design on the Self-Healing Behavior of Cross-Linked Polymers.
abstract: This article describes the manufacturing procedure and the characterization of self-healing polymers based on embedded microvascular networks. The samples were realized by resin casting into water-soluble PVA molds, fabricated via 3D printing. This technology allowed us to exploit the 3D printers' ability to produce complex structures with high resolution for the creation of independent microchannels networks. The two reacting components of a two-part resin could be stored separately within the microstructure. The materials' self-healing ability resulted from their reaction when severe damage caused the healing liquids to leak out, wetting the sample cross section and diffusing one into the other. The mechanical properties of healed samples were investigated by means of uniaxial tensile tests and compared to those of undamaged samples. The effect of microchannel density and different network designs on self-healing efficiency was determined. The different microstructures used were characterized using computerized X-ray microtomography. The versatility of the fabrication technique presented in this work allows conversion of any water-resistant resin into a fully functional self-healing polymeric composite.
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Postiglione
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Alberini
authors.affiliation: School of Engineering, University of Warwick , Coventry CV4 7 AL, U.K.
authors.forename: S
authors.initials: S
authors.lastname: Leigh
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Levi
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
authors.forename: S
authors.identifier: http://orcid.org/0000-0001-8996-0603
authors.initials: S
authors.lastname: Turri
keywords: 3D-printing; micro-CT; microvascular network; self-healing epoxy; silicone