Morphology and properties of neutralized chitosan-cellulosenanocrystals biocomposite films

Abstract

Chitosan/cellulose nanocrystals (CH-CN) films were obtained by casting of dispersions, and treated withNaOH for neutralization proposes. The composition of films was varied from 1 to 10 wt.% of CN. Changesin the morphology of the systems were correlated with the different properties studied. FTIR revealedthe presence of a weak interaction between the polymer matrix and nanofiller, confirmed by a slightlyincrease in thermal stability. SEM images suggested that incorporating CN amounts higher than 3 wt.%generates phase-segregated systems, and SAXS showed that CH avoid the typical organization of CN atconcentrations below 5 wt.%. Improved performance against water was obtained in composite materialscomparing to the pure polymer matrix, as well as CH and CH-CN films did not show antibacterial activitydemonstrating that remnant acetic acid, when no neutralization step is done, plays an important role inthis property.