In this study, the surface polarity of sulfated crystalline nanocellulose (CNC) was tailored using an ecologically compatible surface modification strategy. Lauric arginate, a novel biologically-derived cationic surfactant, was ionically bonded to the CNC surface sulfate groups forming a monolayer that significantly increased surface hydrophobicity. Both unmodified (P-CNC) and surfactant modified (F-CNC) were incorporated into a non-polar PLA matrix to study their reinforcing effect. The P-CNC, ascribed to its inherent hydrophilic characteristic, had limited nucleating and reinforcing effect on the PLA matrix. Large nanoparticle aggregation and interface debonding were easily discernable in P-CNC/PLA nanocomposite films. The hydrophobic F-CNC, by contrast, had a much better dispersibility and interface compatibility within the PLA matrix. The cold crystallization rate, crystallinity, storage modulus (glassy and rubbery states), glass transition temperature, and tensile strength and modulus of F-CNC/PLA nanocomposite films were remarkably enhanced with appropriate loading level of F-CNC (<5 wt%). These results demonstrate an efficient route to increase the hydrophobicity of CNC for its enhanced nanoreinforcing effect in various non-polar matrices.
All Science Journal Classification (ASJC) codes
- Polymers and Plastics