Waterborne acrylic-cellulose nanofibrils nanocomposite latexes via miniemulsion polymerization

Waterborne acrylic-cellulose nanofibrils (CNFs) nanocomposite latexes have been successfully synthesized via one-pot miniemulsion polymerization. A cationic copolymer and a low amount of anionic surfactant were used to promote the stabilization process and prevent the aggregation during storage. The effect of the CNFs content and the amount of added copolymer on the particle size and the stability of the dispersion were studied. Evidence of the binding of CNFs onto the polymer particles was supported by FE-SEM observation. Transparent nanocomposite films were obtained by casting after water evaporation and film-formation process. Investigation of the mechanical properties by dynamic mechanical analysis (DMA) and tensile testing revealed an enhancement in both the stiffness and strength of the nanocomposites, which is indicative that the in-situ polymerization in presence of CNFs did not compromise the strong reinforcing potential of CNFs. The synthesized acrylic-CNFs latexes are able to form films with promising properties for application as waterborne coatings.