Preparation, properties, and mechanism of anionic and cationic cellulose nanocrystals/waterborne polyurethane composite films

Three kinds of cellulose nanocrystals (CNCs) were added into waterborne polyurethane (WPU) and nanocomposite films that prepared by solution casting. The influence different ionic function groups on microstructure properties composite was investigated. Compared with sulfated CNCs (SCNCs) TEMPO oxidized (TOCNCs), FE-SEM images showed cationized (CaCNCs) had better dispersion in films. thermal decomposition these delayed 15 °C compared pure WPU film. tensile strength fracture work CaCNC/WPU film increased 11.9% 8.4%, respectively. light transmittance highest among the 3 films, but its oxygen permeability lowest. In sum, CaCNCs optimal strength, toughness, transmittance, barrier properties, which is consistent good compatibility two components densest structure observed SEM. There may be an attraction hydrogen bonds are expected to have applications food packaging, furniture coatings, biomedical fields.