Szymon Szczepanik

This work introduces a circular biopolymer-based strategy for valorizing keratin-rich industrial residues through the fabrication of biodegradable cotton agrotextiles functionalized with latex–hydrogel coatings. Keratin hydrolysates and gelatin-derived biofertilizer capsules were incorporated into polymer–hydrogel matrices and applied onto cotton substrates to enhance soil moisture regulation and controlled nutrient release. The composite coatings were characterized in terms of water absorption capacity, mechanical performance, biodegradation profiles, and their impact on plant growth using Phaseolus vulgaris as a model species. Hydrogel-rich formulations (LH20 and LH40Z) provided the most favorable balance of tensile strength and controlled degradation while significantly increasing soil moisture availability and overall plant biomass compared with uncoated controls. The gelatin–keratin microcapsules enabled sustained nutrient release and induced a slight increase in soil pH, further supporting plant development. These findings demonstrate the dual functionality of the developed latex–hydrogel coatings as water-management and nutrient-delivery systems and highlight the potential of keratin biowaste upcycling toward high-value, biodegradable agricultural materials aligned with circular economy principles.

Elastomers such as acrylonitrile–butadiene rubber (NBR) are widely used in high-performance applications, yet their intrinsic flammability poses serious safety challenges. This study introduces hybrid nano-additive systems designed to enhance the fire resistance of NBR-based elastomers through the synergistic action of organic, inorganic, and biopolymeric components. The developed formulations incorporate melamine (M), melamine polyphosphate (PM), casein (K), and keratin recovered from industrial waste (P), combined via conventional and hybrid compounding methods. Vulcanization was carried out at 160°C, with optimal curing determined rheometrically. The composites were extensively characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), microcalorimetry, Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and mechanical testing (tensile strength, hardness, aging resistance). The results revealed that hybrid systems, particularly melamine polyphosphate or casein combined with keratin (PPM or PK), reduced heat release rate and combustion efficiency by more than 20% compared to single-component systems. The addition of nanoscale fillers further delayed thermal degradation and improved char stability. This work demonstrates a synergistic flame-retardant mechanism in NBR elastomers, integrating thermal shielding, char formation, and endothermic decomposition pathways. Moreover, the use of biodegradable waste-derived additives enhances the sustainability profile of the materials. The developed hybrid nano-additive systems offer a promising pathway toward eco-efficient, flame-retardant elastomers for applications in sectors with elevated fire hazard, such as automotive, aerospace, and electronics.

Biopolymer blends (GGs) derived from renewable plant or animal‐based raw materials, hold significant potential for competing in the packaging industry by offering environmentally biodegradable and bioresorbable alternatives. One of the main challenges lies in optimizing the mechanical properties to enhance stress transfer between active additives and the gelatin matrices reinforced with modified SiO₂ compounds. In this study, a 5 °C increase in the glass transition temperature and a fourfold improvement in tensile strength (reaching 12 MPa) were achieved by incorporating hydrophilic SiO₂ nanoclay. Ion distribution maps visualized the interactions between silicon derivatives and polypeptide domains within the gel matrix, revealing increased stability attributed to ions such as Si+, SiO+, SiH+, and SiHO+. The absence of heavy metals in the blends underscores their potential as environmentally friendly and sustainable packaging solutions, with promising applications in sectors such as medical packaging.

The study explores innovative crosslinking processes for biopolymer gel materials using amino acids and ion-redox initiators to significantly enhance their structural and functional properties. Advanced analytical techniques, including FTIR, Raman spectroscopy, XRD, TEM, TGA, DSC, ToF-SIMS, SEM/EDS, GPC/SEC, and elemental analysis, were employed for comprehensive material characterization. The synthesized materials show potential applications in packaging and medicine, particularly for single-use products with short life cycles. Two crosslinking strategies were developed. The first combines gelatin with polyvinyl alcohol (PVA); keratin hydrolysate; and amino acids such as cysteine, hydroxyproline, proline, and histidine. The second employs endogenous cysteine, activated by ion-redox initiators, leveraging its trans-sulfuration ability to form highly stable polymer networks with optimized mechanical and thermal properties. Notably, the synergy between cysteine and potassium persulfate redox initiators proved particularly effective, making this approach attractive for industrial applications. This study introduces novel crosslinking methods and highlights the potential of amino acid-based strategies for designing advanced biopolymer gels with enhanced properties.

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%.

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.