Biodegradable Composites with Functional Properties Containing Biopolymers

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.