Fibers were extracted from the pseudostem of the plantain of the variety Hartón, belonging to the order Zingiberales, family Musaceae, genus Musa, species Musa paradisiaca. The fibers were exposed to alkaline treatment to improve their physicomechanical properties for use as reinforcement in green composites. $NaOH$ solutions of 4 %, 5 %, and 6 % by weight were prepared. The fibers were immersed for 2 h in each solution. Fibers were washed with acetic acid to remove $NaOH$ residues and dried at room temperature. Weight loss and lignin, cellulose, and hemicellulose content were evaluated. FTIR, tensile, and elongation tests were performed. SEM images and EDS mapping allowed to conclude the phenomena that occurred in the treatments. The untreated fibers obtained a tensile strength of 37.23 MPa, in contrast to 104.26 MPa obtained by the fibers treated with 5 % NaOH solution. It was concluded that the partial elimination of impurities and waxes improved the mechanical behavior of the fibers by 180 %. Regarding elongation, the fibers treated with 4 % NaOH solution obtained the best result with 3.7 %. It was determined that the partial elimination of lignin favors elongation by 48 %. Excessive hemicellulose removal was found to cause fibril separation and detachment. Considerable contraction of vascular bundles occurred. Roughness in the fibers surface topography were improved.

The present study shows the mercerization process (NaOH) and its effect on the physicochemical characteristics of rice straw. In total, 12 samples were analyzed, 3 as a comparative basis and 9 that were exposed to different concentrations of NaOH (1%, 2%, and 3%) and times, in hours, of exposure in an alkaline environment (1 h, 2 h, and 3 h). The loss of silica and reduction in lignin and hemicellulose contents identified in the chemical characterization allowed for a visualization of the surface topography and cross-section of the treated samples, making it possible to contrast them with the three untreated samples by comparing their roughness, the appearance of their pores, and the contractions of vascular bundles in their conductive tissue. An analysis of the data showed that the results between some treatments were similar, suggesting a reduction in resources in future research. The mechanical resistance allowed for identifying that the NaOH-1%-1 h treatment obtained a better mechanical resistance in the treated samples. However, NaOH-3%-1 h, with the third lowest resistance, obtained the highest % elongation compared to the other samples. These physicochemical changes with NaOH facilitate the selection of the treatment concerning the fiber–matrix interaction and final performance of the composite material that intends to use rice straw as a reinforcing fiber.

La combinación de diversos materiales, ya sea por decisión tecnológica o casualidad, permitió la construcción y conservación de edificaciones antiguas que aún siguen en pie. Buscando replicar las características de estas construcciones, materiales como cal, puzolana, y yeso fueron seleccionados para elaborar un mortero natural y comparar sus propiedades físicas y resistencia a la compresión con las de un mortero tipo portland, con el fin, de establecer una línea base de comportamiento para aplicación en obras civiles. Se empleó una metodología de post prueba únicamente con diseño factorial experimental y grupo intacto. En todas las muestras se presentó sedimentación producida por la diferencia de tamaño de partículas y el fenómeno de exudación, ocasionando bajas resistencias en el material.