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

Abstract

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°C. After reaction, the fibrillated TEMPO-oxidized celluloses were used for preparation of self-standing films and casting of laminate films on 50 lm 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.

Transparent nanocellulose-pigment composite films

“…In the case of Eucalyptus 10 mmol, the obtained films were highly brittle, resulting in relatively large standard deviations for the elastic modulus and lowest elongations at break of all the prepared films. Mechanical properties of the CNF films are similar to those reported by [9,18,25], and poorer than those reported by [13,31]. It is worth mentioning that the differences or similarities in the mechanical properties from/with literature could be in any one, two or all three of the properties, i.e.…”

“…This creates a need for understanding the physical properties of such films to predict their performance as a coating layer. Numerous researchers have investigated the mechanical [9,[11][12][13][14][15][16][17][18][19][20], barrier [21][22][23][24][25] and optical [11,17,[26][27][28][29] properties of neat CNF films and composite CNF films containing clay [30][31][32] or CaCO 3 [32] as reinforcement phase. Comprehensive literature reviews on the same have come up recently [7,[33][34][35][36][37].…”

Properties of hydroxypropyl guar/TEMPO-oxidized cellulose nanofibrils composite films

“…It is well known that the particles with diameters less than one-tenth of the visible-light wavelength do not scatter light (Yang et al 2012;Yano et al 2005). Therefore, the high transparency of the TOCNs film can be attributed to the nano-sized fibers of TOCNs (Rodionova et al 2012c) while the lower transmittance of HPG film is probably due to the remaining cell wall fragments. Otherwise, the introduction of HPG into the composite films increased the particle size, leading to increased light scattering.…”

“…The regular chemical structures of the cellouronic acids in TOCNs film without bulky substituents or additives could contribute to its high oxygen-barrier level (Kato et al 2005). Moreover, the high crystallinity and highly self-aligned elements in TOCNs film were also partially contribute to its superb oxygen-barrier property (Fukuzumi et al 2013b;Rodionova et al 2012c;Wu et al 2012). The loose and cracked structure of pure HPG film diminished its oxygen barrier property.…”

Nanofibrillated Cellulose: Sustainable Nanofiller with Broad Potentials Use

“…As the slurry reached 80 °C at 500 MPa, the suspension turned into a translucent, high consistent gel that they called microfibrillated cellulose (MFC). Since that, MFC opens the way toward intense and promising research on nanocellulose-based material with expanding area of potential applications, including transparent materials (Abe et al 2007a, b;Fukuzumi et al 2009), packaging materials endowed with high mechanical properties, and low gas permeability (Syverud and St enius 2009;Rodionova et al 2011;Spence et al 2011a, b;Aulin et al 2010a, b), biomedical applications (Czaja et al 2007), nanopaper production, and strength additive for paper (Henriksson et al 2009;Sukjoon and Jeffery 2010). NFC could also be used as a thickener additive in foods, cosmetics, paints, and pharmaceutical products (Turbak et al 1983a, b).…”