Biobased composites with peculiar properties offer an attractive route for producing environmentally friendly materials. The reinforcement for poly(butylene adipate-co-terephthalate) (PBAT), based on zein-titanium dioxide (TiO₂) complex (ZTC) microparticles, is presented and used to produce composite filaments, successfully 3-dimensionally (3D) printed by fused deposition modeling (FDM). The outcome of ZTC addition, ranging from 5 to 40 wt %, on the thermo-mechanical properties of composite materials was analyzed. Results reveal that storage modulus increased with increasing the ZTC content, leading to a slight increase in the glass transition temperature. The creep compliance varies with the ZTC concentration, denoting a better resistance to deformation under constant stress conditions for composites with higher complex content. Scanning electron microscopy was used to assess the quality of interphase adhesion between PBAT and ZTC, showing good dispersion and distribution of complex microparticles in the polymer matrix. Infrared spectroscopy confirmed the formation of a valid interface due to the formation of hydrogen bonds between filler and polymer matrix. Preliminary tests on the biocompatibility of these materials were also performed, showing no cytotoxic effects on cell viability. Finally, the 3D printability of biobased composites was demonstrated by realizing complex structures with a commercial FDM printer.

In this work, new biodegradable composite materials based on poly (butylene adipate terephthalate) (PBAT) reinforced with zein–TiO₂ complex microparticles were prepared and characterised by electron microscopy and tensile and dynamic-mechanical tests. The composite pellets were prepared by solvent casting with different filler contents, namely 0, 5.3, 11.1 and 25 part per hundred resin (phr), to modify and modulate the properties of the final materials. Scanning electron microscopy (SEM) images showed homogeneous dispersion of the filler, without microparticles aggregation or phase separation between filler and matrix, suggesting a good interphase adhesion. According to tensile tests, Young’s modulus showed an improvement in the rigidity and the yield stress presented an increasing trend, with opposite behaviour compared to other composites. Dynamic-mechanical analysis (DMA) results exhibited increasing storage modulus values, confirming a greater rigidity with a higher filler percentage. The glass transition temperature showed a slightly increasing trend, meaning the presence of an interaction between the two phases of the composite materials. Overall, the produced PBAT composites showed similar properties to low-density polyethylene (LDPE), proving to be promising and more sustainable alternatives to traditional polymers commonly adopted in agri-food fields.

Mechanical properties of polymer biocomposites are influenced by the interaction between the matrix and the filler surface. In this work, composites based on poly(butylene-adipate-terephthalate) (PBAT) filled with micrometric particles of zein-TiO2 complex (ZTC) were realized via solvent casting technique at different concentrations, equal to 0, 5, 10, and 20 wt%. After pelletization, the resulting materials were injection molded into standard specimens, employed for the uniaxial tensile test (UTT) characterization. From the stress-strain curves, Young’s modulus ( $E$ ), yield stress ( ${\sigma }_y$ ), stress at break ( ${\sigma }_B$ ), elongation at break ( ${\epsilon }_B$ ), and toughness ( $T$ ) were collected. The addition of the ZTC proved to show a reinforcing effect on the polymeric matrix, with an increase in both $E$ and ${\sigma }_y$ . Modelling of the mechanical properties was performed by applying Kerner’s and Pukánszky’s equations. Kerner’s model, applied on experimental $E$ values, returned a very good correspondence between collected and theoretical values. From the application of Pukánszky’s model to ${\sigma }_y$ , the obtained $B$ value showed a good interfacial interaction between the matrix and the filler. Due to the enhanced stiffness of the composites, a reduction in the true stress at break ( ${\sigma }_{T,B}$ ) was observed. The modified Pukánszky’s model gave a $B$ value lower than the one obtained for the yield, but still in the range of acceptable values for microcomposites.

Polyhydroxyalkanoates (PHAs) are a promising class of biobased and biodegradable polymers; however, their inherent brittleness and limited processability hinder widespread application. The glycerol trilevulinate (GT) bioplasticizer has been proposed to enhance the mechanical properties of PHAs without compromising their biodegradability. This study investigates the effect of GT at different concentrations on the anaerobic fermentation of poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) to volatile fatty acids (VFA), focusing on microbial conversion efficiency. These VFA are platform chemicals serving various applications, including resynthesis of PHAs. PHBV/GT blends were characterized in terms of their thermal and morphological properties. The results show that the increased GT percentage reduces the crystallinity and melting temperature, thereby enhancing polymer flexibility. Anaerobic fermentation experiments were conducted using (i) prehydrolyzed PHBV/GT fermentation at fixed 10 wt % GT content and (ii) direct fermentation of PHBV/GT solid particles at different GT concentrations. The findings show that GT-plasticized PHBV was successfully converted into VFA, with acetate and n-butyrate being the predominant fermentation products. While low concentrations of hydrolysate (4-10 g SCOD/L) were efficiently converted, higher concentrations (20 g SCOD/L) did not lead to fermentation, suggesting potential microbial toxicity. The different contents of GT did not affect the microbial conversion process. These findings support the use of GT as plasticizer for PHA-based materials and development of renewable, biodegradable, and microbial recyclable plastic products.

Magnetic nanomaterials offer a versatile platform for advanced information encoding, enabling high data capacity, enhanced counterfeit resistance, and reliable product identification. Here, we present two complementary encoding approaches based on magnetic polymeric supraparticles as miniaturized tags and magnetic particle spectroscopy as the decoding technique. The first exploits variations in nanoparticle composition and polymer matrix to generate one code per tag. The second leverages the nonlinear magnetic response of a single tag under different excitation field conditions, enabling multiple distinguishable codes per tag, shifting the encoding paradigm from material-design to a challenge-response framework. We assess the reliability of the decoding procedure using a dedicated statistical methodology defining reliable distinguishability thresholds. Moreover, translating harmonic spectra into binary keys enables the application of information-theoretic metrics, including Shannon entropy and fractional Hamming distance, to evaluate code robustness and separability. Combined with the robustness of the MPS decoding strategy, these results establish magnetic supraparticles as a scalable platform for high-density, physically secure encoding and authentication.