Thermally-stable photo-curing chemistry for additive manufacturing by direct melt electrowriting

Abstract

In the present study, poly(ε-caprolactone) copolymers decorated with the random inclusion of thermally stable and photo-dimerizing cinnamoyl groups were synthesized for an electrically-assisted material extrusion additive manufacturing technique named melt electrowriting (MEW). The absence of thermally-induced reactions between cinnamoyl groups maintained the molten random copolymers processable at the elevated processing temperature while UV curing could improve thermo-mechanical properties of the films in the solid state. Random inclusion of non-crystallizable photo-reactive co-units was shown to enrich the thermodynamic state of the host polymer with the possibility of the formation of various microstructures, which correlated with the emergence of imperfections, such as spherulitic domains over the profile of fibers printed from molten random copolymers.