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.

摘要

本研究旨在研究碱 (NaOH) 处理对 Yucca Gloriosa (YG) 天然纤维的形态特性和拉伸强度的影响，并优化与此类处理相关的参数。应用响应面法 (RSM) 与中央复合设计 (CCD) 方法设计和分析实验，优化 NaOH 浓度和浸泡时间。此外，还采用扫描电子显微镜 (SEM)、傅里叶变换红外光谱 (FTIR) 和 X 射线衍射 (XRD) 来评估和比较 YG 纤维的形态和结构特性。对于 NaOH 处理过程，预测 YG 纤维的纤维直径和拉伸强度的最佳数学模型分别是线性和二次模型。此外，在最佳工艺条件下实现了最佳数量的 YG 纤维直径和拉伸强度。NaOH 浓度和浸泡时间的优化水平分别为 5 wt.% 和 10 h。因此，在这种条件下进行纤维处理后，与原纤维相比，YG纤维的拉伸强度增加了29.58%，YG纤维的直径减少了7.34%。尽管如此，最佳条件下的碱处理过程并未显着影响 YG 纤维的结构和结晶度。最后，优化条件下的 NaOH 处理，主要是因为改善了形态和拉伸性能，以及增加了天然纤维和聚合物基体之间的界面附着力，在制造多用途杂化复合材料中实际上是有用的。