There is a major focus on natural biopolymers of bacterial, animal, or plant origin as ecological materials, replacing petrochemical products. Biologically derived polylactide (PLA), polyhydroxybutyrate (PHB), and polyhydroxyalkanoates (PHA) possess interesting properties, but they are currently too expensive for most applications. Therefore, researchers try to find other biopolymers that are both durable and cheap enough to replace plastics in some applications. One possible candidate is gelatin, which can be transformed into a thin, translucent film that is flexible and has stable and high mechanical properties. Here, we present a method of synthesizing a composite material from gelatin. For preparation of such material, we used gelatin of animal origin (pig skin) with the addition of casein, food gelatin, glycerin, and enzymes as biocatalysts of chemical modification and further extraction of gelatin from collagen. Compositions forming films with homogeneous shapes and good mechanical properties were selected (Tensile strength reaches 3.11 MPa, while the highest value of elongation at break is 97.96%). After administering the samples to microbial scaring, the composites completely decomposed under the action of microorganisms within 30 days, which proves their biodegradation.

Plastic waste is a serious problem in modern society. Every day, mankind produces tons of waste that must be disposed of or recycled. The most common types of plastic waste are disposable tableware, bags, packaging, bottles, and containers, and not all are recycled. Therefore, there is a great interest in producing environmentally friendly disposable materials. In this study, modified gelatin blends using polysaccharides (e.g., agarose, starch) were produced to obtain a stable coating. Various techniques were used to characterize the obtained bioplastics, including FTIR spectroscopy (Fourier-transform infrared spectroscopy), TGA (thermogravimetric analysis)/DSC (differential scanning calorimetry), contact angle measurements, and surface energy characterization. We also investigated the influence of thermal and microbiological degradation on the properties of the biocomposite. The addition of agarose increased the hardness of the blend by 27% compared to the control sample without added polysaccharides. Increases were also observed in the surface energy (24%), softening point (15%), and glass transition temperature (14%) compared to the control sample. The addition of starch to the biopolymer increased the softening point by 15% and the glass transition temperature by 6%. After aging, both blends showed an increase in hardness of 26% and a decrease in tensile strength of 60%.