Fullerenated Photo-thermo-curable thermoset nanocomposites

The evolution of advanced additive manufacturing (AM) techniques, such as automatic tow placement (ATP), necessitates the development of compatible material systems with enhanced and tunable inherent properties. This study introduces a novel subclass of printable carbon nanocomposites based on a photocurable thermosetting resin, hybridized with graphene flakes (GF) and multiwalled carbon nanotubes (MWCNT). We systematically investigated the effects of varying nanoparticle content ratios separately, GF, MWCNT, and hybrid GF-MWCNT (0.1–0.5 wt%), on the neat printable resin. Our comprehensive characterization revealed that while incorporating carbon-based nanoparticles produced minimal changes in physicochemical properties and the additive manufacturing processability (average viscosity of 0.315 ± 0.017), it significantly altered the material’s thermal properties (residual mass increased monotonically with filler content, reaching up to 7.2% for 0.5 MWCNTs and 8.0% for hybrid GF-MWCNT) at 700 °C. The mechanical responses also exhibited notable changes. Specifically, under quasi-static mechanical loading, the AM process-induced nanoparticle agglomeration acted as a detrimental stress concentrator and voids, particularly degrading the properties of the single-nanoparticle composites, where the elastic modulus decreased from 2.5 ± 0.6 GPa (neat) to an average of 1.1 ± 0.12 GPa for filler contents. In contrast, the dual GF-MWCNT hybrid consistently yielded superior mechanical and thermal properties compared to its individual GF and MWCNT counterparts, achieving performance levels comparable to those of the neat resin. This exceptional performance, particularly when mitigating the negative effects observed under quasi-static loading, demonstrates the significant potential of these carbon-carbon hybrid nanocomposites for future integration with continuous carbon fiber additive manufacturing techniques, paving the way for high-performance structural composites.