Gelatine Blends Modified with Polysaccharides: A Potential Alternative to Non-Degradable Plastics

Non-degradable plastics of petrochemical origin are a contemporary problem of society. Due to the large amount of plastic waste, there are problems with their disposal or storage, where the most common types of plastic waste are disposable tableware, bags, packaging, bottles, and containers, and not all of them can be recycled. Due to growing ecological awareness, interest in the topics of biodegradable materials suitable for disposable items has begun to reduce the consumption of non-degradable plastics. An example of such materials are biodegradable biopolymers and their derivatives, which can be used to create the so-called bioplastics and biopolymer blends. In this article, gelatine blends modified with polysaccharides (e.g., agarose or carrageenan) were created and tested in order to obtain a stable biopolymer coating. Various techniques were used to characterize the resulting bioplastics, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)/differential scanning calorimetry (DSC), contact angle measurements, and surface energy characterization. The influence of thermal and microbiological degradation on the properties of the blends was also investigated. From the analysis, it can be observed that the addition of agarose increased the hardness of the mixture by 27% compared to the control sample without the addition of polysaccharides. In addition, there was an increase in the surface energy (24%), softening point (15%), and glass transition temperature (14%) compared to the control sample. The addition of starch to the gelatine matrix increased the softening point by 15% and the glass transition temperature by 6%. After aging, both compounds showed an increase in hardness of 26% and a decrease in tensile strength of 60%. This offers an opportunity as application materials in the form of biopolymer coatings, dietary supplements, skin care products, short-term and single-contact decorative elements, food, medical, floriculture, and decorative industries.