In this work, cellulose nanocrystals (CNCs), bleached cellulose nanofibers (bCNFs), and unbleached cellulose nanofibers (ubCNFs) isolated by acid hydrolysis from Agave tequilana Weber var. Azul bagasse, an agro-waste from the tequila industry, were used as reinforcements in a thermoplastic starch matrix to obtain environmentally friendly materials that can substitute contaminant polymers. A robust characterization of starting materials and biocomposites was carried out. Biocomposite mechanical, thermal, and antibacterial properties were evaluated, as well as color, crystallinity, morphology, rugosity, lateral texture, electrical conductivity, chemical identity, solubility, and water vapor permeability. Pulp fibers and nanocelluloses were analyzed via SEM, TEM, and AFM. The water vapor permeability (WVP) decreased by up to 20.69% with the presence of CNCs. The solubility decreases with the presence of CNFs and CNCs. The addition of CNCs and CNFs increased the tensile strength and Young’s modulus and decreased the elongation at break. Biocomposites prepared with ubCNF showed the best tensile mechanical properties due to a better adhesion with the matrix. Images of bCNF-based biocomposites demonstrated that bCNFs are good reinforcing agents as the fibers were dispersed within the starch film and embedded within the matrix. Roughness increased with CNF content and decreased with CNC content. Films with CNCs did not show bacterial growth for Staphylococcus aureus and Escherichia coli. This study offers a new theoretical basis since it demonstrates that different proportions of bleached or unbleached nanofibers and nanocrystals can improve the properties of starch films.

Compared to other fibrous materials, plant fibers can act as a reinforcement in plastics due to their relatively high strength and rigidity, low cost, low density, biodegradability, and renewability. In this context, this study examines the effect of the particle size and content of white oak wood flour (Quercus laeta Liemb), obtained from its branches, on the properties of commercial polypropylene. In Mexico, wood from the branches of Quercus laeta Liemb is barely utilized despite its abundance and viability. The main objective of this study is to demonstrate that this waste material can be exploited to prepare useful materials, in this case composites with competitive properties. Tensile and flexural tests, as well as impact strength and melt flow index were evaluated. In addition, density and water absorption capacity were also tested. Results showed that the water absorption increased with the incorporation of wood particles. Mechanical properties were strongly influenced by particle content. A reduction in elongation and strength was observed, while Young’s modulus and flexural modulus increased with the incorporation of wood particles. Impact strength increased with particle size and particle content.

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.

In this work, a photo-polymerization route was used to obtain potassium acrylate-co-acrylamide hydrogels with enhanced mechanical properties, well-defined microstructures in the dry state, and unique meso- and macrostructures in the hydrated state. The properties of the hydrogels depended on the concentration of the crosslinking agent. Mechanical properties, swelling capacity, and morphology were analyzed, showing a well-defined transition at a critical concentration of the crosslinker. In terms of morphology, shape-evolving surface patterns appeared at different scales during swelling. These surface structures had a noticeable influence on the mechanical properties. Hydrogels with structures exhibited better mechanical properties compared to unstructured hydrogels. The critical crosslinking concentration reported in this work (using glycerol diacrylate) is a reference point for the future preparation of multistructured acrylic hydrogel with enhanced properties.

Some plants have great resistance against herbivores, invertebrates, insects, bacteria, and fungi. This resistance is mostly present in plants containing alkaloids, which are the substances responsible for giving them defensive properties. The genus Datura contains tropane alkaloids and all plants from this genus have defensive properties. In this work, we report the toxic effect against fungi of Datura stramonium extracts, obtained by the Petri dish method. The extraction solvents were water, ethanol, 2-propanol, n-butanol, propanone, butanone, 3-methyl-2-pentanone, dichloromethane, xylene, and toluene. The test fungi were Trametes versicolor (L. ex. Fr) Pilát and Rhodonia placenta (Fr.) Niemelä, K.H.Larss. & Schigel. It was found that water, butanone, and toluene extracts promoted mycelial growth, xylene extracts neither inhibited nor promoted mycelial growth, while the other extracts slightly inhibited the growth of these fungi.