| Abstract [eng] |
The growing number of plastic packaging entering landfills and the resulting environmental damage is stimulating interest in alternatives to packaging materials. The focus is on natural packaging materials – biopolymers. Perhaps the most widely used biopolymers are polysaccharides. These materials are used to coat a variety of foods, thus forming a protective layer, or to produce films for packaging. Polysaccharide films have a good gas barrier and mechanical properties but are quite sensitive to moisture. To improve the existing properties, the polysaccharides are mixed with other polysaccharides or with other substances, thus forming a biocomposite. Layered biocomposites of cellulose and different concentrations of polysaccharides (pectin, starch, agar, sodium alginate and calcium alginate) without and with plasticizer (1, 2.5 and 5%) were formed during the research work. Glycerol was used as a plasticizer in this study. The properties of the obtained biocomposites were evaluated by determinations of moisture content, water solubility, water vapor permeability, and contact angle. After evaluating the obtained results, it was found that biocomposites without plasticizer were less flexible. It was also found that the cellulose / agar and cellulose / calcium alginate biocomposites without plasticizer had the highest shrinkage due to coating drying and increasing polysaccharide concentration in the coating. The surface of the biocomposites was assessed by optical microscopy to form solid polysaccharide coatings. Studies have shown that the presence of a plasticizer affects the moisture, water solubility, water vapor permeability, and contact angle of the biocomposite. Studies also have shown that increasing the concentration of plasticizer increases the moisture, water solubility, and water vapor permeability of the biocomposite, but decreases the contact angle of the surface. |
