scholarly journals Cellulose Nanofibril (CNF) Films and Xylan from Hot Water Extracted Birch Kraft Pulps

2019 ◽  
Vol 9 (16) ◽  
pp. 3436 ◽  
Author(s):  
Marc Borrega ◽  
Hannes Orelma
Keyword(s):  
Food Packaging ◽  
Kraft Pulp ◽  
Barrier Properties ◽  
Hot Water ◽  
Kraft Pulps ◽  
Cellulose Nanofibril ◽  
Vapour Permeability ◽  
Transparent Films ◽  
Cnf Films ◽  
Birch Kraft Pulp

The effects of xylan extraction from birch kraft pulp on the manufacture and properties of cellulose nanofibril (CNF) films were here investigated. Hot water extractions of bleached and unbleached kraft pulps were performed in a flow-through system to remove and recover the xylan. After the extraction, the pulps were oxidized with 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and fibrillated in a high-pressure microfluidizer. Compared to CNF from bleached kraft pulp, the CNF dispersions obtained from water-extracted pulps were less viscous and generally contained a higher amount of microfiber fragments, although smaller in size. In all cases, however, smooth and highly transparent films were produced from the CNF dispersions after the addition of sorbitol as plasticizer. The CNF films made from water-extracted pulps showed a lower tensile strength and ductility, probably due to their lower xylan content, but the stiffness was only reduced by the presence of lignin. Interestingly, the CNF films from water-extracted bleached pulps were less hydrophilic, and their water vapour permeability was reduced up to 25%. Therefore, hot water extraction of bleached birch kraft pulp could be used to produce CNF films with improved barrier properties for food packaging, while obtaining a high-purity xylan stream for other high-value applications.

Upgrading of paper-grade pulps to dissolving pulps by nitren extraction: Optimisation of extraction parameters and application to different pulps

Holzforschung ◽  
2006 ◽  
Vol 60 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Ron Janzon ◽  
Jürgen Puls ◽  
Bodo Saake
Keyword(s):  
Kraft Pulp ◽  
Cellulose Degradation ◽  
The Other ◽  
Decisive Factor ◽  
Kraft Pulps ◽  
Chemical Pulps ◽  
Dissolving Pulps ◽  
Sulfite Pulp ◽  
Extraction Parameters ◽  
Birch Kraft Pulp

Abstract Xylans were selectively removed from paper-grade pulps by nitren extraction to produce dissolving pulps. Extraction parameters were optimised for a birch kraft pulp regarding time, temperature, liquor/pulp ratio, and total nitren charge. Furthermore, the applicability of the method was investigated for two other kraft pulps obtained from eucalyptus and mixed softwood, and for one beech sulfite pulp. Extracted pulps were characterised regarding their carbohydrate content and Cuen viscosity. The nitren charge was a decisive factor for xylan removal and pulp purity. The combination of a high nitren concentration and low liquor/pulp ratio was most effective for xylan removal. However, a high liquor/pulp ratio with a lower nitren concentration proved to be more selective and minimised cellulose degradation as well. Glucomannans were almost insoluble under the extraction conditions investigated. Therefore, softwood pulps were not suitable for the upgrading of chemical pulps to dissolving pulps by nitren extraction. On the other hand, hardwood pulps obtained by kraft and sulfite processes contained 96–97% cellulose after nitren extraction.

scholarly journals Xylan Hemicellulose: A Renewable Material with Potential Properties for Food Packaging Applications

2021 ◽  
Vol 13 (24) ◽  
pp. 13504
Author(s):  
Petronela Nechita ◽  
Roman Mirela ◽  
Florin Ciolacu
Keyword(s):  
Food Packaging ◽  
Pathogenic Bacteria ◽  
Water Solubility ◽  
Barrier Properties ◽  
High Water ◽  
Hydroxyl Groups ◽  
Vapour Permeability ◽  
Coated Papers ◽  
Starting Point ◽  
Renewable Material

Xylan hemicelluloses are considered the second most abundant class of polysaccharides after cellulose which has good natural barrier properties necessary for foods packaging papers and films. Xylan exists today as a natural polymer, but its utilisation in packaging applications is limited and not sufficiently analysed. In this study, the performances of hardwood xylan hemicellulose in forming uniform films and as biopolymer for paper coatings were analysed. The xylan-coated paper and film samples were tested regarding their water, air, and water vapour permeability, water solubility, mechanical strength, and antimicrobial activity against pathogenic bacteria. Structural analyses of xylan hemicelluloses emphasised a high number of hydroxyl groups with high water affinity. This affects the functional properties of xylan-coated papers but can facilitate the chemical modification of xylan in order to improve their hydrophobic properties and extend their areas of application. The obtained results unveil a promising starting point for using this material in food packaging applications as a competitive and sustainable alternative to petroleum-based polymers.

scholarly journals Influence of Lactic Acid Surface Modification of Cellulose Nanofibrils on the Properties of Cellulose Nanofibril Films and Cellulose Nanofibril–Poly (Lactic Acid) Composites

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1346
Author(s):  
Ruth Anayimi Lafia-Araga ◽  
Ronald Sabo ◽  
Omid Nabinejad ◽  
Laurent Matuana ◽  
Nicole Stark
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Water Absorption ◽  
Aqueous Medium ◽  
Cellulose Nanofibrils ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Esterification Reaction ◽  
Cellulose Nanofibril ◽  
Cnf Films

In this study, cellulose nanofibrils (CNFs) were modified by catalyzed lactic acid esterification in an aqueous medium with SnCl2 as a catalyst. Films were made from unmodified and lactic acid-modified CNF without a polymer matrix to evaluate the effectiveness of the modification. Ungrafted and lactic acid-grafted CNF was also compounded with poly(lactic acid) (PLA) to produce composites. Mechanical, water absorption, and barrier properties were evaluated for ungrafted CNF, lactic acid-grafted CNF films, and PLA/CNF composites to ascertain the effect of lactic acid modification on the properties of the films and nanocomposites. FTIR spectra of the modified CNF revealed the presence of carbonyl peaks at 1720 cm−1, suggesting that the esterification reaction was successful. Modification of CNF with LA improved the tensile modulus of the produced films but the tensile strength and elongation decreased. Additionally, films made from modified CNF had lower water absorption, as well as water vapor and oxygen permeability, relative to their counterparts with unmodified CNFs. The mechanical properties of PLA/CNF composites made from lactic acid-grafted CNFs did not significantly change with respect to the ungrafted CNF. However, the addition of lactic acid-grafted CNF to PLA improved the water vapor permeability relative to composites containing ungrafted CNF. Therefore, the esterification of CNFs in an aqueous medium may provide an environmentally benign way of modifying the surface chemistry of CNFs to improve the barrier properties of CNF films and PLA/CNF composites.

Barrier Properties Analysis of Polyethylene Terephthalate Films (PET) Coated with Natural Polyphenolic and Gelatin Mixture (PGM)

2018 ◽  
Vol 382 ◽  
pp. 38-43 ◽  
Author(s):  
Shagufta Ishtiaque ◽  
Shahina Naz ◽  
Jawaad Ahmed ◽  
Arshad Faruqui
Keyword(s):  
Polyethylene Terephthalate ◽  
Food Packaging ◽  
Oxygen Transfer Rate ◽  
Barrier Properties ◽  
Vapour Permeability ◽  
Barrier Materials ◽  
Oxygen Penetration ◽  
Green Tea Leaves ◽  
Film Formulation ◽  
Pet Films

The food packaging material provides protection against moisture, heat, enzymes, oxygen penetration etc. The shelf life of food can be increased by coating barrier materials on plastic films. In this work the oxygen transfer rate (OTR) and water vapour permeability (WVP) of Polyethylene terephthalate (PET) films were adjusted via coating of Polyphenols and Gelatin mixture (PGM) with different concentrations while maintaining the other properties of modified PET films. This article deals with the changes in properties of PGM coated PET films with some innovative ideas of multilayer film formulation. Polyphenolics were extracted from Terminalia Catappa (Indian almond), Camellia sinensis (Green tea leaves) and Trachyspermumammi (Ajwain). The results showed that WVP was decreased from 1.0±0 to 0.12±0.03 g/in2/day (p < 0.01) in comparison with uncoated (1.3±0.07g/in2/day). Similarly, same trend was obtained for OTR (63.5±0.02 to 38.1±0.03g/in2/day) with respect to uncoated film (82 ± 3.5). This study provides important evidence that addition of PGM on PET films leads to improved films in terms of OTR and WVP with minor changes in optical properties.

Influence of Nanocellulose Additive on the Film Properties of Native Rice Starch-based Edible Films for Food Packaging

2020 ◽  
Vol 13 (3) ◽  
pp. 222-233 ◽  
Author(s):  
Jeya Jeevahan ◽  
Manoharan Chandrasekaran
Keyword(s):  
Mechanical Strength ◽  
Food Packaging ◽  
Food Additives ◽  
Barrier Properties ◽  
Edible Films ◽  
Rice Starch ◽  
Oxygen Scavenger ◽  
Film Properties ◽  
Vapour Permeability ◽  
Starch Films

Background & Objective: Starch-based edible films, which are transparent, odourless, biodegradable, tasteless, and semi-permeable to gases and food additives, have attracted the attention of the research community as the alternative food packaging materials to synthetic plastics. However, they pose poor water resistance and mechanical strength that should be improved for food packaging application. Few relevant patents to the topic have been reviewed and cited. Methods: Inclusion of nanoadditives in starch films can not only improve their mechanical and barrier properties but also can act as antimicrobial agent, oxygen scavenger, and biosensor. The present investigation is focussed on the effects of nanocellulose extracted from banana pseudostems on the film properties of rice starch-based edible films. Nanocellulose was extracted from dried banana pseudostems through isolation of cellulose and acid hydrolysis. Rice starch-based edible films were prepared through solution casting by adding nanocellulose of varying concentrations (0%, 2%, 4%, 6%, 8% & 10%). Results: The film properties, such as Water Vapour Permeability (WVP), mechanical strength (tensile strength, Young's modulus and percentage of elongation), film solubility in water and film colour, were determined. The test results were discussed and the effects of nanocellulose additives were studied. Conclusion: From the results, it was clear that the addition of nanocellulose had improved the film properties, making the rice starch-based edible films a promising choice for food packaging applications.

scholarly journals Preparation and Characterization of Films Based on Disintegrated Bacterial Cellulose and Montmorillonite

2020 ◽  
Author(s):  
Agata Sommer ◽  
Hanna Staroszczyk ◽  
Izabela Sinkiewicz ◽  
Piotr Bruździak
Keyword(s):  
Bacterial Cellulose ◽  
Food Packaging ◽  
Barrier Properties ◽  
Packaging Material ◽  
Mechanical And Thermal Properties ◽  
Natural Polymers ◽  
Vapour Permeability ◽  
Water Barrier ◽  
Bond Network

AbstractThe food packaging materials from natural polymers including polysaccharides offer an ecologically important alternative to commonly used synthetic, non-biodegradable counterparts. The purpose of this work was to modify of bacterial cellulose (BC) leading to the improvement of its functional properties in terms of use as a food packaging material. Effects of disintegration of BC and addition of montmorillonite (MMT) on its water barrier, mechanical and thermal properties were investigated. Disintegration of BC increased its water vapour permeability (WVP) and thermal stability, but decreased its tensile strength (σ). These changes were closely related to the rearrangement of hydrogen-bond network in the BC structure, resulting in a partial conversion from the Iα to Iβ allomorph. The addition of 2% of MMT did not affect WVP and σ of the disintegrated BC (bBC), while the plasticization of the modified bBC generally decreased WVP, and did not increase σ. The improvement in water barrier properties of bBC modified by adding 2% of MMT in the presence of glycerol was caused by the formation of hydrogen bonds between the components of the composite. The results presented show the potential usefulness of BC modified by disintegration and adding 2% of MMT and 10–15% of glycerol as a food packaging material.

scholarly journals Gelatin-Based Antimicrobial Films Incorporating Pomegranate (Punica granatum L.) Seed Juice by-Product

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 166 ◽  
Author(s):  
Arantzazu Valdés ◽  
Esther Garcia-Serna ◽  
Antonio Martínez-Abad ◽  
Francisco Vilaplana ◽  
Alfonso Jimenez ◽  
...  
Keyword(s):  
Food Packaging ◽  
Active Material ◽  
Barrier Properties ◽  
Punica Granatum ◽  
Total Phenolic ◽  
Vapour Permeability ◽  
Casting Technique ◽  
Potential Strategy ◽  
Main Components ◽  
Punica Granatum L

Pomegranate (Punica granatum L.) seed juice by-product (PSP) was added as reinforcing and antimicrobial agent to fish gelatin (FG) films as a promising eco-friendly active material for food packaging applications. A complete linkage analysis of polysaccharides in PSP showed xylan and cellulose as main components. This residue showed also high total phenolic content and antioxidant activity. Three formulations were processed by adding PSP to FG (0, 10, 30 wt. %) by the casting technique, showing films with 10 wt. % of PSP the best performance. The addition of PSP decreased elongation at break and increased stiffness in the FG films, particularly for 30 wt. % loading. A good compatibility between FG and PSP was observed by SEM. No significant (p < 0.05) differences were obtained for barrier properties to oxygen and water vapour permeability compared to the control with the incorporation of PSP, whereas water resistance considerably increased and transparency values decreased (p < 0.05). High thermal stability of films and inhibition against S. aureus were observed. The addition of PSP at 10 wt. % into FG was shown as a potential strategy to maintain the integrity of the material and protect food against lipid oxidation, reducing huge amounts of pomegranate and fish wastes.

scholarly journals Effect of glycerol plasticizer loading on the physical, mechanical, thermal, and barrier properties of arrowroot (Maranta arundinacea) starch biopolymers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Tarique ◽  
S. M. Sapuan ◽  
A. Khalina
Keyword(s):  
Food Packaging ◽  
Barrier Properties ◽  
Glycerol Concentration ◽  
Cross Sectional ◽  
Vapour Permeability ◽  
Solubility In Water ◽  
Elongation At Break ◽  
Casting Technique ◽  
Solution Casting Technique ◽  
Film Making

AbstractThis research was set out to explore the development of arrowroot starch (AS) films using glycerol (G) as plasticizer at the ratio of 15, 30, and 45% (w/w, starch basis) using solution casting technique. The developed films were analyzed in terms of physical, structural, mechanical, thermal, environmental, and barrier properties. The incorporation of glycerol to AS film-making solution reduced the brittleness and fragility of films. An increment in glycerol concentration caused an increment in film thickness, moisture content, and solubility in water, whereas density and water absorption were reduced. The tensile strength and modulus of G-plasticized AS films were reduced significantly from 9.34 to 1.95 MPa and 620.79 to 36.08 MPa, respectively, while elongation at break was enhanced from 2.41 to 57.33%. FTIR analysis revealed that intermolecular hydrogen bonding occurred between glycerol and AS in plasticized films compared to control films. The G-plasticized films showed higher thermal stability than control films. The cross-sectional micrographs revealed that the films containing 45% glycerol concentration had higher homogeneity than 15% and 30%. Water vapour permeability of plasticized films increased by an increase in glycerol concentrations. The findings of this research provide insights into the development of bio-degradable food packaging.

Prebleaching of eucalypt kraft pulp with OP stages: Effect of an acid pretreatment or chelation step

TAPPI Journal ◽  
2012 ◽  
Vol 11 (6) ◽  
pp. 31-38
Author(s):  
TATIANA M. PÓVOAS ◽  
DINA A.G. ANGÉLICO ◽  
ANA P.V. EGAS ◽  
PEDRO E.G. LOUREIRO ◽  
LICÍNIO M. GANDO-FERREIRA ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Comparative Evaluation ◽  
Kraft Pulp ◽  
Kraft Pulps ◽  
Acid Pretreatment ◽  
High Brightness ◽  
Pulp Viscosity ◽  
Brightness Reversion

We conducted a comparative evaluation of different treatments for the bleaching of eucalypt kraft pulps beginning with OP stages. The treatments tested were (1) an acid chelation stage with DTPA (OQP sequence); (2) a hot acid stage (AOP sequence); and (3) a chelant addition into the alkaline oxygen stage ((OQ)P and A(OQ)P sequences). The latter strategy was also studied for environmental reasons, as it contributes to the closure of the filtrate cycle. The OQP sequence leads to the highest brightness gain and pulp viscosity and the lowest peroxide consumption caused by an efficient metals control. Considering that the low biodegradability of the chelant is a problem, the A(OQ)P sequence is an interesting option because it leads to reduced peroxide consumption (excluding OQP) while still reaching high brightness values and similar brightness reversion to OQP prebleaching, with only a viscosity loss of 160 dm3/kg. Therefore, a hot acid stage could be considered when a separate acid Q stage is absent in a prebleaching sequence of Eucalyptus globulus kraft pulps involving OP stages.

Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

TAPPI Journal ◽  
2010 ◽  
Vol 9 (9) ◽  
pp. 47-53 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Chlorine Dioxide ◽  
Previous Investigation ◽  
Kraft Pulp ◽  
Energy Costs ◽  
Alkaline Extraction ◽  
Stage Versus ◽  
Kraft Pulps ◽  
Steam Consumption ◽  
Elemental Chlorine ◽  
Softwood Kraft Pulp

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

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