Reinforced polymeric composites with natural fibers have garnered significant interest in recent years due to the need for biomass utilization and the requirements of various industries, such as automotive and construction. Among these natural fibers, Agave lechuguilla fiber, commonly known as ixtle (FIx) or Tampico fiber, exhibits important characteristics such as length, high strength, and durability. However, there is limited literature on its conditioning, functionalization, and utilization as a reinforcing material in polymeric composites (CP). This study presents the optimization of the alkali-silane treatment of FIx, identifying the most suitable reaction conditions to enhance their thermal stability, tensile strength, and silane coupling agent (ACSi) grafting on the fiber surface. The chemical treatment with ACSi proved highly effective, resulting in a significant grafting content, which was confirmed through FTIR and SEM–EDS analyses. The high level of functionalization did not compromise the mechanical performance of the fibers, suggesting that functionalized FIx holds great potential as a reinforcing material in CP. These findings open new paths for the sustainable use of Agave lechuguilla fibers, contributing to the development of environmentally friendly and high-performance polymeric composites in various industrial applications.

The development of small semiconductor molecules such as the maleiperinone, have gained importance due to their applications in optoelectronics. In this work semiconductor films composed by a polymer matrix of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) and maleiperinone were manufactured. The films used in the studies were deposited by vacuum evaporation and spin-coating techniques. Atomic force microscopy (AFM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Infrared spectroscopy were used for the analysis of morphological and structural films. The fundamental and the onset of the direct and indirect band gaps were also obtained by UV-vis spectroscopy. The band-model theory and the Density-functional theory (DFT) calculations were applied to determine the optical parameters. The dipole moment is 3.33 Db, and the high polarity gives a signal of the heterogeneous charge distribution along the structure of maleiperinone. Simple devices were made from the films and their electrical behavior was subsequently evaluated. The presence of the polymer decreased the energy barrier between the film and the anode, favoring the transport of charges in the device. Graphene decreased the absorption and its ohmic behavior make it a candidate to be used as a transparent electrode in optoelectronic devices. Finally, the MoO₃ provides a behavior similar to a dielectric.

This study introduces a novel approach to improving the functional performance of document coatings through the development of a chitosan-modified epoxy-acrylate varnish intended for application on the specialized substrate used in banknotes. In this first phase, the work focuses exclusively on assessing the thermal, mechanical, and optical behavior of the varnish films to establish the technical feasibility of incorporating chitosan into this type of high-security coating. Chemical characterization was conducted via FTIR, while DSC and DMA were used to evaluate the thermal transitions and viscoelastic properties of the cured films at different chitosan concentrations. Gloss measurements were used to quantify the visual impact on the coating. The results reveal a systematic increase in crosslinking and stiffness with higher chitosan content, accompanied by a reduction in gloss. Formulations containing 1% and 5% chitosan emerge as the most technically viable, maintaining adequate mechanical integrity and appearance while enabling future antimicrobial enhancement. The antimicrobial properties of chitosan-based films, central to the next stage of this research, will be reported in subsequent work. This first-stage evaluation provides a solid foundation for integrating biopolymer additives into security and commercial printing technologies, advancing the development of sustainable functional coatings.