مقداد کمالی مقدم

The present study addressed the isolation of cellulose microfibers (CMF) from Yucca leaves using chemical treatments. This study was conducted in three stages, namely, two stages of alkaline treatments (NaOH 3%), and a single stage of bleaching treatment (H2O2 6%). The resulting microfibers were characterized using Scanning Electron Microscope (SEM), X-Ray diffraction (XRD), Fourier Transform Infra-red (FTIR), and Thermogravimetric Analysis (TGA). Alkaline and oxidative bleaching treatments had a positive impact on defibrillation and morphology of the fibers by the partial removal of noncellulosic materials. FTIR results also revealed that most of the amorphous components were removed through proper alkali and bleaching treatments from the fibers. Further, SEM analysis showed that cellulose microfibers with an average diameter of 7 µm were successfully isolated with a yield of about 25%. The crystallinity index (76%) and crystallite size (3.41 nm) of CMF were also determined through the XRD analysis. The method used in this study led to the isolation of the microfibers with the thermal stability of 215°C and activation energy of 67.72 kJ/mol. The values obtained in this study were reasonably promising for the use of Yucca cellulose microfibers in various applications, such as reinforced-polymer manufacturing.