Abstract
This work demonstrates the application of pilot-scale surface functionalization of cellulose nanofibrils (CNFs) by aqueous grafting-through polymerization and subsequent spray drying in 3D printed poly(lactic acid) (PLA) composites. Grafted-CNF composites attain an ultimate tensile strength of 88 ± 3 MPa and a tensile modulus of elasticity of 7.8 ± 1.3 GPa in the printing direction at 20 wt% reinforcement loading. These increases, 42% and 139% over neat PLA, respectively, represent the strongest reported 3D printed CNF/PLA composite to date in the literature. The mechanisms behind these improvements are investigated by comparisons to neat PLA and unmodified spray-dried CNF/PLA controls using melt rheology, dynamic mechanical analysis, and assessment of the reinforcement dispersion. These experiments reveal that improved network formation and shear-induced alignment of the grafted CNFs facilitate the remarkable tensile properties of the printed composites.
| Original language | English |
|---|---|
| Pages (from-to) | 111-124 |
| Number of pages | 14 |
| Journal | RSC Applied Polymers |
| Volume | 3 |
| Issue number | 1 |
| DOIs | |
| State | Published - Nov 15 2024 |
Funding
This material is based upon work supported by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Materials and Manufacturing Office under CPS Agreement 35863, and Oak Ridge National Laboratory/University of Maine SM2ART program with research and resources used at the Manufacturing Demonstration Facility (MDF), a DOE AMMTO User Facility; the Advanced Structures and Composites Center (ASCC), a University of Maine research center; and the University of Maine. The authors thank Dr Emma Perry of the University of Maine electron microscope laboratory for her support and assistance in this work. They would also like to thank Wesley Bisson and Spencer Sansouci of the University of Maine Advanced Structures and Composite Center for their assistance with the composite 3D printing. This material is based upon work supported by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Materials and Manufacturing Office under CPS Agreement 35863, and Oak Ridge National Laboratory/University of Maine SMART program with research and resources used at the Manufacturing Demonstration Facility (MDF), a DOE AMMTO User Facility; the Advanced Structures and Composites Center (ASCC), a University of Maine research center; and the University of Maine. The authors thank Dr Emma Perry of the University of Maine electron microscope laboratory for her support and assistance in this work. They would also like to thank Wesley Bisson and Spencer Sansouci of the University of Maine Advanced Structures and Composite Center for their assistance with the composite 3D printing.