Properties of cyclic olefin-based photo-ROMP resins suitable for DLP 3D printing applications

Abstract

A series of cyclic olefin monomers, all based on derivatives of tetracyclododecene with different pendant groups, were evaluated as suitable candidates for photo-ROMP resins using a latent Ru precatalyst activated by a chlorinated thioxanthone (CPTX, 1-chloro-4-propoxythioxanthone) when exposed to purple light. Two monomers where the pendant group was hexyl or phenethyl are non-flammable and exhibited low volatility and odor. The thermomechanical properties of these two resins were determined after flood photo-curing. The high reactivity and excellent shelf-life photo-ROMP system augmented with a light absorber and base quencher allowed for production of DLP 3D printed parts. The thermomechanical properties of the 3D printed specimens were comparable to those of flood cured parts.