Worldwide, improper disposal of plastics is instigating environmental initiatives to combat plastics accumulation of in the environment and the world’s oceans. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites with Miscanthus (Misc) fibres and distillers’ dried grains with solubles (DDGS) were studied to ascertain if natural fibres and proteinaceous fillers can improve polyhydroxyalkanoate marine biodegradability. Using ASTM standard D7991-15, the biodegradation of PHBV, PHBV with Misc (15 and 25 wt%) and PHBV with DDGS (15 and 25 wt%) was performed in a simulated marine environment for the first time, as indicated by a literature survey. PHBV/Misc (85/15) and (75/25) biocomposites showed 15 and 25% more biodegradation compared to PHBV, respectively. Proteinaceous PHBV/DDGS (85/15) and (75/25) biocomposites showed 17 and 40% more biodegradation compared to PHBV, respectively. Furthermore, PHBV/Misc (75/25) and PHBV/DDGS (75/25) biocomposites were marine biodegraded in 412 and 295 days, respectively. In conclusion, proteinaceous fillers (DDGS) biocomposites have better marine biodegradability than miscanthus.

In order to provide a second economic life to agave fibers, an important waste material from the production of tequila, filaments based on polylactic acid (PLA) were filled with agave fibers (0, 3, 5, 10 wt%), and further utilized to produce biocomposites by fused deposition modeling (FDM)-based 3D printing at two raster angles (−45°/45° and 0°/90°). Differential scanning calorimetry, water uptake, density variation, morphology, and composting of the biocomposites were studied. The mechanical properties of the biocomposites (tensile, flexural, and Charpy impact properties) were determined following ASTM international norms. The addition of agave fibers to the filaments increased the crystallinity value from 23.7 to 44.1%. However, the fibers generated porous structures with a higher content of open cells and lower apparent densities than neat PLA pieces. The printing angle had a low significant effect on flexural and tensile properties, but directly affected the morphology of the printed biocomposites, positively influenced the impact strength, and slightly improved the absorption values for biocomposites printed at −45°/45°. Overall, increasing the concentrations of agave fibers had a detrimental effect on the mechanical properties of the biocomposites. The disintegration of the biocomposites under simulated composting conditions was slowed 1.6-fold with the addition of agave fibers, compared to neat PLA.

In this work, the suitability for the production of sustainable and lightweight materials with specific mechanical properties and potentially lower costs was studied. Agave fiber (AF), an agro-industrial waste, was used as a reinforcement and azodicarbonamide (ACA) as a chemical blowing agent (CBA) in the production of bilayer materials via rotational molding. The external layer was a composite of linear medium density polyethylene (LMDPE) with different AF contents (0–15 wt %), while the internal layer was foamed LMDPE (using 0–0.75 wt % ACA). The samples were characterized in terms of thermal, morphological and mechanical properties to obtain a complete understanding of the structure-properties relationships. Increases in the thicknesses of the parts (up to 127%) and a bulk density reduction were obtained by using ACA (0.75 wt %) and AF (15 wt %). Further, the addition of AF increased the tensile (23%) and flexural (29%) moduli compared to the neat LMDPE, but when ACA was used, lower values (75% and 56% for the tensile and flexural moduli, respectively) were obtained. Based on these results, a balance between mechanical properties and lightweight can be achieved by selecting the AF and ACA contents, as well as the performance and aesthetics properties of the rotomolded parts.

Photopolymerized microparticles are made of biocompatible hydrogels like Polyethylene Glycol Diacrylate (PEGDA) by using microfluidic devices are a good option for encapsulation, transport and retention of biological or toxic agents. Due to the different applications of these microparticles, it is important to investigate the formulation and the mechanical properties of the material of which they are made of. Therefore, in the present study, mechanical tests were carried out to determine the swelling, drying, soluble fraction, compression, cross-linking density ($M_c$) and mesh size ($\xi$) properties of different hydrogel formulations. Tests provided sufficient data to select the best formulation for the future generation of microparticles using microfluidic devices. The initial gelation times of the hydrogels formulations were estimated for their use in the photopolymerization process inside a microfluidic device. Obtained results showed a close relationship between the amount of PEGDA used in the hydrogel and its mechanical properties as well as its initial gelation time. Consequently, it is of considerable importance to know the mechanical properties of the hydrogels made in this research for their proper manipulation and application. On the other hand, the initial gelation time is crucial in photopolymerizable hydrogels and their use in continuous systems such as microfluidic devices.

Nowadays, solving the problems associated with environmental pollution is of special interest. Therefore, in this work, the morphology and thermal and mechanical properties of extruded fibers based on polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) added to prickly pear flour (PPF) under composting for 3 and 6 months were evaluated. The highest weight loss percentage (92 ± 7%) was obtained after 6-month degradation of the PLA/PBAT/PPF/CO/AA blend, in which PPF, canola oil (CO), and adipic acid (AA) were added. Optical and scanning electron microscopy (SEM) revealed structural changes in the fibers as composting time increased. The main changes in the absorption bands observed by Fourier transform infrared spectroscopy (FTIR) were related to the decrease in -C=O (1740 cm⁻¹) and -C-O (1100 cm⁻¹) groups and at 1269 cm⁻¹, associated with hemicellulose in the blends with PPF. Differential scanning calorimetry (DSC) showed an increase in the cold crystallization and melting point with degradation time, being more evident in the fibers with PPF, as well as a decrease in the mechanical properties, especially Young’s modulus. The obtained results suggest that PPF residues could promote the biodegradability of PLA/PBAT-based fiber composites.

In this work, microfibrillated cellulose (MFC) from ash branch wood was used as reinforcement in a thermoplastic starch matrix to develop environmentally friendly materials. Pulp fibers and MFCs were characterized by SEM, TEM, and FTIR. Corn starch biofilms were prepared via casting, formulating eight biofilms with 5 and 10 wt% of MFC. Also, extracts of Muicle and Hibiscus were added to incorporate antibacterial properties. The biofilms were evaluated for mechanical, thermal, and antibacterial properties. Also, properties such as color, opacity, morphology, electrical conductivity, contact angle, and solubility, among others, were evaluated. The reinforced biofilms were homogeneous, dimensionally stable, and transparent with slight color changes. MFC incorporation enhanced hydrogen bonding, which increased the ultimate tensile strength from 11.2 MPa to approximately 19–21 MPa and the Young’s modulus from 809 MPa to 1034–1192 MPa. The presence of MFC also reduced solubility from 48.7% to 38.7–39.8% and decreased water vapor permeability by about 20–23% in biofilms with 10 wt% MFC. Gas barrier properties and the glass transition temperature depended on extract type and fiber content, indicating greater rigidity. The use of ash-based MFC encourages the implementation of circular economy strategies and the development of sustainable biocomposites.