The reinforcing effect of lignin‐containing cellulose nanofibrils in the methacrylate composites produced by stereolithography

Lignin‐containing nanocellulose has been used as a potential reinforcement in the three‐dimensional (3D) printed materials due to its high aspect ratio and favorable compatibility with 3D printed polymer matrix. However, lignin‐containing cellulose nanocrystal (L‐CNC) only performed its reinforcement at elevated temperature during postcure process. This not only complicates the 3D printing process, but also increases the energy consumption of 3D printing. Therefore, in this study, we applied the lignin‐containing cellulose nanofibrils (L‐CNF) to reinforce the 3D printed methacrylate (MA) resin and the reinforcing mechanism of L‐CNF with a simple material process was investigated. Mechanical, thermal, and rheological properties of the 3D printed composites were systematically analyzed. It was observed that the mechanical and thermal properties of 3D printed composites were enhanced with the addition of L‐CNF due to its distinguished characters of surfacial‐coated lignin and high aspect ratio, which increase the mechanical interaction between L‐CNF and MA matrix. Lignin‐containing cellulose nanofibril was applied to reinforce the 3D printed methacrylate. Mechanical and thermal properties of 3D printed composites were enhanced with addition of 0.1% L‐CNF. L‐CNF has great advantages in reinforcing the 3D printed composites than L‐CNC, due to its high aspect ratio, simple material process, and energy saving characters. The L‐CNF reinforced 3D printed composites fabricated by a simple material process will have a great potential to be used in the structural and electrical applications.