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Developing plastic/fluorine/silicon-free and degradable water/oil-resistant coatings for paper-based packaging materials to replace disposable plastic products is a very effective way to solve the problem of 'white pollution' or microplastics pollution. A novel water/oil-resistant coating was developed by alkyl ketene dimer (AKD)-based Pickering emulsion and chitosan in this work. Cellulose nanofibrils (CNF) were used as a stabilizing solid for AKD emulsion, with the addition of chitosan as an oil-resistance agent. The coating provides excellent hydrophobicity, water/oil resistance as well as good barrier properties. The water contact angle was as high as 130° and the minimum Cobb60 value was 5.7 g/m 2 , which was attributed to the hydrophobicity of AKD. In addition, the kit rating reached maximum 12/12 at coating weight of 8.26 g/m 2 and the water vapor transmittance rate (WVTR) was reduced to 153.4 g/(m 2 ⋅day) at the coating weight of 10.50 g/m 2 . The tensile strength of the paper was increased from 28.1 to 43.6 MPa after coating. Overall, this coating can effectively improve the performance of paper-based materials, which may play an important role in the process of replacing disposable plastic packaging with paper-based materials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study focuses on enhancing the strength and water stability of paper straws through a novel approach involving a binary emulsion of lignin-based polyurethane and chitosan. Kraft lignin serves as the raw material for synthesizing a blocked waterborne polyurethane, subsequently combined with carboxylated chitosan to form a stable binary emulsion. The resulting emulsion, exhibiting remarkable stability over at least 6 months, is applied to the base paper. Following emulsion application, the paper undergoes torrefaction at 155 °C. This process deblocks isocyanate groups, enabling their reaction with hydroxyl groups on chitosan and fibers, ultimately forming ester bonds. This reaction significantly improves the mechanical strength and hydrophobicity of paper straws. The composite paper straws demonstrate exceptional mechanical properties, including a tensile strength of 47.21 MPa, Young's modulus of 4.33 GPa, and flexural strength of 32.38 MPa. Notably, its water stability is greatly enhanced, with a wet tensile strength of 40.66 MPa, surpassing commercial paper straws by 8 folds. Furthermore, the composite straw achieves complete biodegradability within 120 days, outperforming conventional paper straws in terms of environmental impact. This innovative solution presents a promising and sustainable alternative to plastic straws, addressing the urgent need for eco-friendly products., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The effect of Fenton's reagent (FR) on surface and dispersion properties of black liquor (BL) was investigated. These properties were compared to those of indulin C (IC), a commercial lignin, and egg lecithin (Le). FR was applied at two different bulk concentrations of H2O2 (160 and 320 mM). At pH 8, a minimum in surface tension for the Fenton treated BL was observed. The dispersant ability of BL, IC and Le in oil-in-water (O/W) emulsions was studied by measuring emulsion stability and drop size. It was found that the surface activity and emulsifying capability of BL were higher than those of IC. The emulsifying capability of Le was improved by the FR treatment at low H2O2 concentration.

The article analyzes the separation of fats from paper waste packaging. The method is based on interaction with boiling water and greaseproof paper. The cooking process is considered the formation of emulsions according to different slots. The research data are presented and discussed obtained from the analysis of ready-made samples. 20 different fat-coated paper samples have been prapared for research. Ten of them have been selected for printing paper, and another dozen cartons. The half of the samples analyzed are covered with vegetable fat, the remaining samples are vegetable fat. It was found that the carton samples were less opposed to the separation of fat. During the experiment, it was determined that by cooking the cardboard samples coated with olive oil for 5 minutes, 30% of the total fat content was removed. The most effective samples of this type were heated for a long time. [ABSTRACT FROM AUTHOR]

Adhesives have a wide range of applications in various industries. Water based emulsion adhesives being used in printing industry are most often based on polyvinyl acetate (PVAc) homopolymers, especially in bookbinding for short run book production and caseing in. Designing durable and quality short run products requires understanding the interactions between used materials in adhesive joint and the basic components of paper and adhesive. In this study, the adhesive parameters of PVAc adhesive on five paper samples containing different shares of inorganic fillers have been investigated. Paper samples were investigated in the terms of surface roughness, moisture, ash and CaCO3 content. Besides the different paper properties, the varying amount of water (0%, 2.5%, 5%) in adhesive have been studied as well. PVAc adhesive was applied on all samples under the same conditions (23°C a nd 50% RH) a nd method. The analysis of the surface free energy (SFE) and its polar and dispersive components of paper and adhesive was performed by contact angle measurements. There was no large impact on SFE of hydrophilic adhesive samples due to added amount of water. According to the obtained results, the interfacial free energy between two phases and mechanical work of the adhesion was calculated. [ABSTRACT FROM AUTHOR]

Using biobased polyelectrolytes to emulsify natural fatty molecules is one possible key technology to create sustainable materials. The emulsions can be used in papermaking instead of synthetic hydrophobizing agents or in nonwoven manufacturing to create strong, hydrophobic textile-like materials. This article investigates a novel emulsification system based on a polyelectrolyte complex between chitosan dissolved in citric acid and carboxymethyl cellulose together with sunflower (Helianthus annuus) oil. Viscose nonwoven treated with the emulsion had a contact angle of over 120°. Tensile tests showed that the produced paper and nonwoven materials achieved high dry and, especially, high wet strength. Infrared spectroscopy illuminated the impact of heat curing the binder, and electron microscopy showed that the oil droplets from the emulsion were spread across the fibre surface. The results from this study enable sustainable nonwovens to be applied in areas where high dry and wet strength and water repellence are required; this includes outdoor applications, including agricultural mulch films, where nonwoven is used frequently and a sustainable approach is urgently needed to reduce the accumulation of plastics in the environment. [Display omitted] • Polyelectrolyte complex based on chitosan and carboxymethyl cellulose can emulsify sunflower oil. • The emulsion can be used as a biobased binder to replace fossil-based binders in nonwoven. • Cellulosic material treated with the binder receive high dry- and wet strength. • Contact angles of more than 120° can be reached with the emulsion-based polyelectrolyte complex binder. [ABSTRACT FROM AUTHOR]

Fluorochemical-treated paper was tested to determine the amount of migration that occurs into foods and food-simulating liquids and the characteristics of the migration. Migration characteristics of fluorochemicals from paper were examined in Miglyol, butter, water, vinegar, water-ethanol solutions, emulsions and pure oil containing small amounts of emulsifiers. Additionally, microwave popcorn and chocolate spread were used to investigate migration. Results indicate that fluorochemicals paper additives do migrate to food during actual package use. For example, we found that microwave popcorn contained 3.2 fluorochemical mg kg-1 popcorn after popping and butter contained 0.1 mg kg-1 after 40 days at 4°C. Tests also indicate that common food-simulating liquids for migration testing and package material evaluation might not provide an accurate indication of the amount of fluorochemical that actually migrates to food. Tests show that oil containing small amounts of an emulsifier can significantly enhance migration of a fluorochemical from paper. [ABSTRACT FROM AUTHOR]