The effect of chemical composition on microfibrillar cellulose films from wood pulps: water interactions and physical properties for packaging applications

Abstract

The interactions with water and the physical properties of microfibrillated celluloses (MFCs) and associated films generated from wood pulps of different yields (containing extractives, lignin, and hemicelluloses) have been investigated. MFCs were produced by combining mechanical refining and a high pressure treatment using a homogenizer. The produced MFCs were characterized by morphology analysis, water retention, hard-to-remove water content, and specific surface area. Regardless of chemical composition, processing to convert macrofibrils to microfibrils resulted in a decrease in water adsorption and water vapor transmission rate, both important properties for food packaging applications. After homogenization, MFCs with high lignin content had a higher water vapor transmission rate, even with a higher initial contact angle, hypothesized to be due to large hydrophobic pores in the film. A small amount of paraffin wax, less than 10%, reduced the WVTR to a similar value as low density polyethylene. Hard-toremove water content correlated with specific surface area up to approximately 50 m 2 /g, but not with water retention value. The drying rate of the MFCs increased with the specific surface area. Hornified fibers from recycled paper also have the potential to be used as starting materials for MFC production as the physical and optical properties of the films were similar to the films from virgin fibers. In summary, the utilization of lignin containing MFCs resulted in unique properties and should reduce MFC production costs by reducing wood, chemical, and energy requirements.

Nanocellulose in Thin Films, Coatings, and Plies for Packaging Applications: A Review

“…Accordingly, various researchers have explored ways to render cellulose-based films resistant to wetting (Aulin et al 2009b;Spence et al 2010b;Rodionova et al 2011;Yang et al 2012;Abdollahi et al 2013b;Kisonen et al 2015;Visanko et al 2015). Spence et al (2010b) and Rojo et al (2015) showed that contact angles of water on cellulosic films tend to increase with increasing lignin content within the range from about 1 to 14% lignin. Contact angles were reduced, thereby increasing water-wettability in cases where the films had been extracted with a benzene/ethanol mixture.…”

“…Rather, efforts to minimize penetration by aqueous fluids generally have focused on decreasing the water-wettability of the nanocellulose-based barrier films (Yang et al 2012;Kisonen et al 2015). Measurements of the contact angle of water have been employed as a criterion for identifying promising formulations to achieve resistance to liquid water (Spence et al 2010b;Rodionova et al 2011Rodionova et al , 2012aYang et al 2012;Pereda et al 2014;Kisonen et al 2015;Rojo et al 2015;Visanko et al 2015). …”

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

“…When microfibrillated cellulose materials of different lignin and extractives contents were exposed to an organic solvent to remove any extractives, the water-cellulose interactions as measured by water contact angle all increased, with the largest increases observed for the material with the most extractives initially (Spence et al 2010). However, a search of the literature revealed a paucity of studies attempting to correlate levels of extractives and extents of swelling or absorbency.…”

Deflocculation of Cellulosic Suspensions with Anionic High Molecular Weight Polyelectrolytes

“…Because NFC surfaces have high hygroscopicity and swelling ability (Spence et al 2010), they were stabilized by pumping a buffer solution of 10 mmol/L of NaCl (pH 8) through the QCM-D measurement cell before the adsorption experiments. In the adsorption measurements concentrations of APAMs were 0.025 g/L.…”