Strengthening and toughening 3D printing of photocured resins by thermal expansion microspheres

High cross-linking density thermally cured epoxy resin typically results in brittle nature. 3D printing technology of a photocurable resin modified by thermally expandable microspheres is proposed in this paper to overcome these limitations. The addition of appropriate amounts of thermally expandable microspheres into the UV-cured epoxy resin can improve the tensile strength, bending strength, elongation at break, and impact strength. Therefore, thermally expandable microspheres can strengthen and toughen the epoxy resin. In addition, the effects of different amounts of UV-cured resins modified with thermally expandable microspheres on various mechanical properties are systematically analyzed. Moreover, the toughening mechanism of thermally expandable microspheres and their influence on thermal performance are also studied.