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Free-standing, robust, and transparent bioplastics were obtained by blending cellulose and naringin at different proportions. Optical, thermal, mechanical, antioxidant, and antimicrobial properties were systematically investigated. In general, the incorporation of naringin produced important UV blocking and plasticizer effects and good antioxidant and antibacterial properties. Moreover, the barrier properties were characterized by determination of their water and oxygen transmission rates, finding that both parameters decreased by increasing the naringin content and reaching values similar to other petroleum-based plastics and cellulose derivatives used for food packaging applications. Finally, the biodegradability of these films was determined by measurement of the biological oxygen demand (BOD) in seawater, demonstrating an excellent decomposition in such conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

The fabrication of pectin-cellulose nanocrystal (CNC) biocomposites has been systematically investigated by blending both polysaccharides at different relative concentrations. Circular free-standing films with a diameter of 9 cm were prepared by simple solution of these carbohydrates in water followed by drop-casting and solvent evaporation. The addition of pectin allows to finely tune the properties of the biocomposites. Textural characterization by AFM showed fibrous morphology and an increase in fiber diameter with pectin content. XRD analysis demonstrated that pectin incorporation also reduced the degree of crystallinity though no specific interaction between both polysaccharides was detected, by ATR-FTIR spectroscopy. The optical properties of these biocomposites were characterized for the first time and it was found that pectin in the blend reduced the reflectance of visible light and increased UV absorbance. Thermal stability, analyzed by TGA, was improved with the incorporation of pectin. Finally, pectin-cellulose nanocrystal biocomposites showed a good biodegradability in seawater, comparable to other common bioplastics such as cellulose and low-molecular weight polylactide, among others. • Pectin and CNC have been blended at different proportions to form biocomposites. • No interaction between both polysaccharides was detected by ATR-FTIR spectroscopy. • Pectin modifies morphology, crystallinity, physical properties, and biodegradation. [ABSTRACT FROM AUTHOR]

The valorization of vegetable waste can create opportunities to produce new valuable bioplastics. In this study, a one-step process to fully convert a variety of vegetable waste materials into bioplastic films is reported. The process is carried out in a diluted aqueous HCl solution at room temperature, it is easily scalable, and with no environmental concerns associated with the use of organic or dangerous chemicals. The generated bioplastics are completely biodegradable and environmentally friendly. Freestanding, flexible bioplastic films were obtained from vegetable waste like carrot, parsley, radicchio and cauliflower. They have similar mechanical properties with other bioplastics, like thermoplastic starch, and showed to have little migration in a food simulant. The color and the functional properties (i.e. antioxidant capability) of the starting vegetables are preserved in the bioplastics, thanks to the mild conditions of the fabrication process. The new conversion process allows the blending of the bioplastics with other natural or synthetic polymers, in order to improve their mechanical and gas barrier properties, like the oxygen permability (OP), thus expanding their field of applications. Poly vinyl alcohol (PVA)/carrot bioplastic film showed an OP of 31.2 cm3μm m−2 day−1 kPa−1, which is lower than the OP for other synthetic films, like high density polyethylene films (HDPE), and similar to edible materials like chitosan. [ABSTRACT FROM AUTHOR]

Tridecafluorononanoic acid (TFNA), a C6-fluorinated carboxylic acid, was esterified with cellulose at different molar ratios (0:1, 1:1, 2:1, and 3:1) in a trifluoroacetic acid (TFA):trifluoroacetic anhydride (TFAA):CHCl 3 (2:1:1, v:v:v) solvent mixture. Free-standing films were obtained for all formulations and are presented as alternatives to composites and blends of paper with fluorinated molecules. Mechanical properties were investigated by tensile tests, and a plasticizer effect of fluorinated chains was observed. Interestingly, the wettability of these new cellulose derivatives was similar or even better than other common cellulose derivatives and fluorinated polymers employed in food packaging. Hydrodynamic properties were also improved by addition of TFNA, resulting in materials with water vapor permeability values comparable to other cellulose-based food packaging materials. In addition, films with the higher amounts of TFNA showed the required oil resistance for papers used in food packaging applications, as determined by the Kit Test. Finally, the biodegradation of these C6-fluorinated cellulose esters, assessed by biological oxygen demand (BOD) in seawater, was higher than typical bio-based polymers used in food packaging. The bioplastic synthesized at a molar ratio 1:1 (TFNA:cellulose) showed excellent performances in terms of greaseproof, hydrophobicity, ductility, and biodegradability, representing a sustainable alternative to typical plastics used in food packaging. [Display omitted] • A C6-fluorinated carboxylic acid was esterified with cellulose. • Control of fluorinated content allows to tune physical properties. • These cellulose esters are greaseproof, biodegradable, and hydro- and oleophobic. • They are good alternatives to simple blends of fluorinated molecules with paper. [ABSTRACT FROM AUTHOR]

Bioplasticswith a wide range of mechanical properties were directlyobtained from industrially processed edible vegetable and cereal wastes.As model systems, we present bioplastics synthesized from wastes ofparsley and spinach stems, rice hulls, and cocoa pod husks by digestingin trifluoroacetic acid (TFA), casting, and evaporation. In this way,amorphous cellulose-based plastics are formed. Moreover, many othernatural elements present in these plants are carried over into thebioplastics rendering them with many exceptional thermo-physical properties.Here, we show that, due to their broad compatibility with cellulose,amorphous cellulose can be naturally plasticized with these bioplasticsby simply mixing during processing. Comparison of their mechanicalproperties with that of various petroleum based synthetic polymersindicates that these bioplastics have equivalent mechanical propertiesto the nondegrading ones. This opens up possibilities for replacingsome of the nondegrading polymers with the present bioplastics obtainedfrom agro-waste. [ABSTRACT FROM AUTHOR]

In this context, the works published in this Special Issue have addressed such a topic from different perspectives, including bio-based alternatives to petroleum-based polymers [[3], [8], [12]], bioplastics for packaging [[2], [4], [10]] and other industrial uses [[6]], and sustainable food waste management and biorefinery [[1], [5], [11]]. 31963296 10 Correa-Pacheco Z.N., Black-Solís J.D., Ortega-Gudiño P., Sabino-Gutiérrez M.A., Benítez-Jiménez J.J., Barajas-Cervantes A., Bautista-Baños S., Hurtado-Colmenares L.B. Preparation and Characterization of Bio-Based PLA/PBAT and Cinnamon Essential Oil Polymer Fibers and Life-Cycle Assessment from Hydrolytic Degradation. The valorization of biomass from different renewable resources (i.e., agriculture, food, forestry, fishery, etc.) by green processes to produce multifunctional polymers with potential industrial applications is a smart strategy to substitute non-biodegradable petroleum-based plastics [[1], [3], [5], [7], [9], [11]]. Correa-Pacheco et al. prepared bio-based cinnamon essential oil-containing PLA/PBAT fibers by melt mixing of both polymers and subsequent extrusion where the essential oil was incorporated [[10]]. [Extracted from the article]

Free-standing films ha v e been obtained by drop-casting cellulose-glycerol mixtures (up to 50 wt% glycerol) dissolved in trifluoroacetic acid and trifluoroacetic anhydride (TFA:TFAA, 2:1, v:v). A comprehensive examination of the optical, structural, mechanical, thermal, hydrodynamic, barrier, migration, greaseproof, and biodegradation characteristics of the films was conducted. The resulting cellulose-glycerol blends exhibited an amorphous molecular structure and a reinforced H-bond network, as evidenced by X-ray diffraction analysis and infrared spectroscopy, respectively. The inclusion of glycerol exerted a plasticizing influence on the mechanical properties of the films, while keeping their transparency. Hydrodynamic and barrier properties were assessed through water uptake and water vapor/oxygen transmission rates, respectively, and obtained values were consistent with those of other cellulose-based materials. Furthermore, overall migration levels were below European regulation limits, as stated by using Tenax® as a dry food simulant. In addition, these bioplastics demonstrated good greaseproof performance, particularly at high glycerol content, and potential as packaging materials for bakery products. Biodegradability assessments were carried out by measuring the biological oxygen demand in seawater and high biodegradation rates induced by glycerol were observed. • TFA:TFAA solves cellulose and glycerol, forming amorphous films after solvent evaporation. • Glycerol addition plasticizes the films, maintaining transparency. • Glycerol enhances grease resistance while keeping low migration levels. • High biodegradation in seawater indicates the environmental friendliness of blends. [ABSTRACT FROM AUTHOR]

A mixture of trifluoroacetic acid:trifluoroacetic anhydride (TFA:TFAA) was used to dissolve chitin from shrimp shells. Free-standing films were prepared by blending the chitin solution and glycerol at different percentages, followed by drop-casting, and the complete evaporation of the solvents. After this process, the chitin matrix showed an amorphous molecular structure, as determined by X-ray diffraction. Optical, mechanical, thermal, and antioxidant properties were also thoroughly investigated. The incorporation of glycerol induced a plasticizing effect on the mechanical response of films and improved their transparency. In addition, hydrodynamic and barrier properties were determined by contact angle and water vapor/oxygen transmission rates, respectively, and revealed typical values of other polysaccharides. These bioplastics also presented an excellent greaseproof behavior with the highest degree of oil repellency as determined by the Kit test. Moreover, the overall migration was evaluated by using Tenax® as a dry food simulant and levels were compliant with European regulations. Their antifungal properties were tested using Botrytis cinerea as a model. Biodegradability was also determined by measuring the biological oxygen demand in seawater. Degradation rates were high and similar to those of other fully-degradable materials. [Display omitted] • TFA:TFAA solvent mixture was used to dissolve chitin. • Chitin structure was amorphous after the evaporation of the solvents. • The use of glycerol as a plasticizer controls the mechanical properties. • Chitin-glycerol bioplastics are transparent, grease resistant, and biodegradable. [ABSTRACT FROM AUTHOR]