(351d) Additive Manufacturing Using Olefin Metathesis

The additive manufacturing (AM) of thermoset polymers has been limited primarily to radical or cationic photopolymerizations, restricting available resins and attainable material properties. Ring-opening metathesis polymerization (ROMP) has emerged as a useful mechanism for the printing of thermoset materials with advantageous high-performance properties. However, previous demonstrations of ROMP for AM have been hindered by sluggish printing rates and restricted to a small number of patterned layers or simple geometries. Here, we present the use of photosensitizers and latent ruthenium catalysts to accelerate the photo-initiated ROMP of dicyclopentadiene resins for the 3D printing of tough, high-performance thermosets. Both UV-assisted direct-ink write (DIW) AM and stereolithography (SLA) AM are demonstrated. Notably, continuous SLA AM is achieved by employing a photo-base generator to yield a catalyst deactivation layer adjacent to the projection window. With the use of the resin system described, DIW and continuous-SLA printing rates of 60 mmâ‹…s^-1 and 180 mm h^-1 are demonstrated.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.