Effectiveness of alkaline and hydrothermal treatments on cellulosic fibers extracted from the Moroccan Pennisetum Alopecuroides plant: Chemical and morphological characterization

Abstract

This work aims to study the physical, chemical, and thermal properties of natural fibers extracted from the Pennisetum alopecuroides plant. The study was carried out on raw and treated fibers to assess improvements that facilitate future uses in composites. The alkaline treatment was carried out using NaOH with different concentrations (1, 3, 5, and 10%) for 2 hours. Hydrothermal treatment was performed at different immersion times in a water bath at 100°C. The chemical composition of Pennisetum alopecuroides fibers, such as cellulose, hemicellulose, lignin, and ash contents, was evaluated. The structure of the fiber was analyzed by FTIR, SEM, and X-ray diffraction. Thermogravimetric analysis (TGA) is used to study the thermal stability of the fiber. The density was also investigated with the pycnometric methode. The results showed that a concentration of 3% NaOH during the 2h is the most suitable solution to treat the P.alopecuroides fiber, but the hydrothermal treatment for 1h at 100°C is also effective for this fiber. The treated fibers seem viable to be used as reinforcement for composites production, namely to achieve goals of energy efficiency.