Extraction of cellulose fiber from banana pseudo-stem using chemical pretreatment and ultrasonic

In this research, cellulose is extracted from banana pseudo stem by using chemical pretreatment followed by ultrasonic. Isolation of pure cellulose is difficult and different ultrasonic amplitudes and time affect the yield and properties of cellulose. The objectives of this study are to isolate cellulose from banana pseudo-stem by chemomechanical method and to determine the effect of ultrasonic amplitude and time on the yield of cellulose. The chemical used are sodium chlorite used as bleaching treatment to remove the lignin while potassium hydroxide acts as alkaline treatment to remove the hemicellulose and pectin. The chemically treated cellulose is proceed to ultrasonic for different ultrasonic time (15 minutes, 30 minutes and 45 minutes) and different amplitude (25 %, 50 % and 75 %). The cellulose composition of banana pseudo stem is 31.6 %. Chemical treated followed by ultrasonic cellulose has better properties than chemical treated cellulose. Thus, chemomechanical method is more effective in extracting the cellulose from banana pseudo stem. Ultrasonic time with 30 minutes and 25 % amplitude showed the best yield of cellulose (92.59 %). The morphology of cellulose are analyzed by SEM. The diameter of chemical treated cellulose is 15.690 μm. However, the chemical treated follow by ultrasonic with 30 minute and 75 % amplitude of cellulose show reduction in diameter with 1.418 μm. The ultrasonic time for 15 minutes and 75 % amplitude showed the highest crystallinity index (58.8 %). This is due to high amplitude can remove the amorphous region. The highest thermal stability of cellulose is obtained from ultrasonic with 30 minutes and 25 % amplitude showed that cellulose start to decompose at 280 °C. Result show that the removal of lignin, hemicellulose and pectin are confirmed by FTIR. Different properties of the cellulose can be applied in different application. Results from this work may be potentially applied in textile, paper, bioethanol, cellulose acetate, food packaging and thermoplastic polymer.