scholarly journals Skin and bubble formation in films made of methyl nanocellulose, hydrophobically modified ethyl(hydroxyethyl)cellulose and microfibrillated cellulose

Cellulose ◽  
2020 ◽  
Author(s):  
Johanna Lyytikäinen ◽  
Maria Morits ◽  
Monika Österberg ◽  
Isto Heiskanen ◽  
Kaj Backfolk
Keyword(s):  
Methyl Cellulose ◽  
Microfibrillated Cellulose ◽  
Hydroxyethyl Cellulose ◽  
Effect Of Temperature ◽  
Cellulose Derivatives ◽  
Air Bubbles ◽  
Oxygen Transmission Rate ◽  
Hydrophobically Modified ◽  
Film Forming ◽  
Ethyl Hydroxyethyl Cellulose

AbstractThe use of nanomaterials and polymers from renewable resources is important in the search for sustainable alternatives to plastic-based packaging materials and films. In this work, self-supporting thin films prepared from derivatized and non-derivatized nanocellulose and cellulose derivatives were studied. The effect of drying temperature on the film-forming behavior of compositions comprising hydrophobically modified ethyl(hydroxyethyl)cellulose (EHEC), native microfibrillated cellulose (MFC) and nanocellulose made from methyl cellulose was determined. The interaction between the components was assessed from viscosity measurements made at different temperatures, the result being linked to a thermal-dependent association during liquid evaporation, and the subsequent barrier and film-forming properties. The effect of temperature on suspensions was clearly different between the materials, confirming that there were differences in interaction and association between EHEC–MFC and methyl nanocellulose–MFC compositions. The amphiphilic EHEC affected both the suspension homogeneity and the film properties. Air bubbles were formed under certain conditions and composition particularly in MFC films, dependent on the drying procedure. The presence of air bubbles did not affect the oxygen transmission rate or the oil and grease resistance. An increasing amount of MFC improved the oxygen barrier properties of the films.

The role of MFC and hydrophobically modified ethyl(hydroxyethyl)cellulose in film formation and the barrier properties of methyl nanocellulose film

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Johanna Lyytikäinen ◽  
Sami-Seppo Ovaska ◽  
Isto Heiskanen ◽  
Kaj Backfolk
Keyword(s):  
Contact Angle ◽  
High Performance ◽  
Film Formation ◽  
Barrier Properties ◽  
Hydroxyethyl Cellulose ◽  
Hydrophobically Modified ◽  
Coated Materials ◽  
Ethyl Hydroxyethyl Cellulose ◽  
Nanocellulose Film

Abstract There is currently a great demand for sustainable and bio-derived coatings for fiber-based packaging materials, which are technically implementable with a high performance. The aim of this work was to investigate the grease resistance of coatings prepared from methyl nanocellulose when applied on paperboard. Co-additives selected from native microfibrillated cellulose (MFC) and hydrophobically modified ethyl(hydroxyethyl)cellulose (EHEC) were used in order to determine their impact on film formation and crack resistance for folds. Small and moderate coat weights were applied in order to determine the critical coat weight for the barrier properties. It was found that high grease resistance can be achieved with methyl nanocellulose and a combination of methyl nanocellulose and MFC coatings. Contact angle determinations for water on uncoated and coated materials showed that EHEC-MFC films have a very high contact angle which is due to both the surface chemistry and roughness. This indicates and confirms that EHEC may facilitate the wetting of oil and greases. Methyl nanocellulose mixed with hydrophobically modified EHEC significantly changed the barrier properties indicating a change in the film formation.

scholarly journals Film formation and foamability of cellulose derivatives: Influence of co-binders and substrate properties on coating holdout

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 597-613
Author(s):  
Johanna Lyytikäinen ◽  
Sami-Seppo Ovaska ◽  
Isto Heiskanen ◽  
Kaj Backfolk
Keyword(s):  
Film Formation ◽  
Hydrophobic Surface ◽  
Hydroxyethyl Cellulose ◽  
Cellulose Derivatives ◽  
Hydrophobically Modified ◽  
Substrate Properties ◽  
Foam Forming ◽  
Water Holding ◽  
Good Coating

Foams were prepared from hydrophobically modified ethyl(hydroxyethyl) cellulose (EHEC), methyl nanocellulose, and native microfibrillated cellulose (MFC). Their film- and foam-forming abilities, stabilities, and suitabilities for foam coating on different substrates were investigated. The role of EHEC as a polymeric stabilizing agent was also studied. The EHEC-MFC foams showed greater stability and water-holding ability under pressurized dewatering than MFC foams prepared in the presence of a surfactant. A foam could be created with methyl nanocellulose without any foaming agent. Selected nanocellulose gels and foam formulations were used to coat various substrates. The surface was efficiently closed by gel and foam coatings prepared from the methyl nanocellulose and EHEC solutions, which was ascribed to good coating holdout. Coatings on papers with different levels of smoothness/density and hydrophobicity/ hydrophilicity confirmed that foam-substrate interactions affected the coat quality. The air permeance was reduced by 99% and 64% with a methyl nanocellulose coating and an EHEC-MFC coating, respectively. An EHEC-MFC coating created a hydrophobic surface on a hydrophilic substrate, and methyl nanocellulose improved the oil resistance even at a low coat weight.

Sign in / Sign up

Export Citation Format

Share Document