Surface Modification of Cellulose Nanocrystals and Their Application as a Reinforcing Material for Polylactic Acid
Christopher L. Kitchens
Cellulose nanocrystals (CNC) have the potential to serve as reinforcement for polylactic acid (PLA), which has become a widely-used polymer for biodegradable products, but some deficiencies still need to be overcome. The main goal of this work is to improve the properties of the PLA by the addition of surface-modified CNC in the polymer matrix and thus obtaining a polymer with broader applications. CNC were isolated from cotton by acid hydrolysis combined with an esterification surface-modification and further functionalized with different surfactants. Phase behavior of modified CNC was studied in organic solvents by visual examination and polarized microscopy. PLA-CNC films were prepared and characterized by Instron universal testing machine and polarized microscopy. The stability of the surface-modified CNC was significantly improved in organic solvents and was also found to show self-organization at steady and shearing conditions. Modified CNC increased the toughness of PLA by 37%, while maintaining the tensile properties at low CNC contents. The nanocomposites showed remarkable optical properties when increasing the CNC content thus having interesting potential applications. It can be concluded that surface modification of CNC with surfactants improves the interactions of the nanomaterials with organic media and enhances the mechanical and optical properties of PLA-CNC nanocomposites.
Orellana, Jose Luis and Kitchens, Christopher L., "Surface Modification of Cellulose Nanocrystals and Their Application as a Reinforcing Material for Polylactic Acid " (2013). Graduate Research and Discovery Symposium (GRADS). 45.