Effect of Alkali Treatment on Diameter and Tensile Properties of Yucca Gloriosa Fiber Using Response Surface Methodology

Abstract

ABSTRACT The present study aimed to investigate the effect of alkali (NaOH) treatment on the morphological properties and tensile strength of Yucca Gloriosa (YG) natural fibers along with the optimization of the parameters related to such treatment. The Response Surface Methodology (RSM) with Central Composite Designs (CCD) approach for the design and analysis of experiments with the optimization of NaOH concentration and immersion time was applied. Also, the Scanning Electron Microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were also employed to evaluate and compare the morphological and structural properties of YG fibers. For NaOH treatment process the best mathematical models to predict the fiber diameter and tensile strength of the YG fibers were the linear and quadratic models, respectively. Additionally, the optimal amount of YG fibers diameter and tensile strength were achieved at optimum process conditions. The optimized levels for NaOH concentration and immersion time were 5 wt.% and 10 h, respectively. So that, after fiber treatment in this condition, tensile strength of YG fibers was increased by 29.58% and the diameters of YG fibers were decreased by 7.34% compared to the raw fibers. Nonetheless, the process of alkali treatment in optimum conditions did not significantly affect the structural and crystallinity of YG fibers. Finally, NaOH treatment under optimal condition, mainly because of improving the morphological and tensile properties as well as increasing the interfacial adhesion between natural fibers and polymer matrices, is practically useful in the manufacture of multi-purpose hybrid composites.