Additive Manufacturing of Poly(dicyclopentadiene) and Carbon-Fiber Composites via Heating at a Patterned Photothermal Interface

Abstract

We report vat-type additive manufacturing (AM) of poly(dicyclopentadiene) (pDCPD) and carbon-fiber (CF) composites via heating at a patterned photothermal interface (HAPPI) by using thermo-responsive polysulfone (PSU)-encapsulated Hoveyda-Grubbs second generation catalyst (HG2) polymer microparticles (PSU-HG2 PMPs). Photothermal conversion of light to thermal energy in HAPPI enabled the release of HG2 in the resin followed by localized thermal curing according to the dictated light pattern. Complex structures of pDCPD were generated by controlling the amount of the catalyst microparticles, print conditions (temperature, speed, and layer thickness), and aging time for the resin mixture prior to AM. In addition to pDCPD parts, AM of pDCPD-CF composites was also enabled by HAPPI and facilitated by the fact that HAPPI AM does not impose limits on the optical properties of the resin. We describe the mechanical performance of pDCPD and composite specimens produced via HAPPI AM, and present microstructural studies from SEM and CT analyses. HAPPI AM is demonstrated as a useful tool to create complex three-dimensional (3D) structures of pDCPD and tensile test specimens of pDCPD-CF composites from vat-like AM.