Mechanical and oxygen barrier properties of films prepared from fibrillated dispersions of TEMPO-oxidized Norway spruce and Eucalyptus pulps

TEMPO-oxidized cellulose nanofibers (TOCN) were obtained from commercial Norway spruce and mixed Eucalyptus cellulose pulps using TEMPO/sodium bromide (NaBr)/sodium hypochlorite (NaClO) system at pH 10 and 22 A degrees C. After reaction, the fibrillated TEMPO-oxidized celluloses were used for preparation of self-standing films and casting of laminate films on 50 mu m thick polyethylene terephthalate. Significant differences between N. spruce and Eucalyptus TOCN were registered. The tensile strength of the films showed a maximum value for spruce samples oxidized with addition of 10 mmol g(-1) of NaClO. Oxygen permeability decreased with increasing oxidation levels, being lower for N. spruce TOCN compared to Eucalyptus.