Microwave assisted extraction of cellulose from lemon grass: Effect on techno-functional and microstructural properties

Abstract

The study focused on utilizing lemon grass straw to generate cellulose through the process of delignification, which involves the removal of hemicelluloses, followed by bleaching. The study involves the microwave-assisted alkali extraction, followed by characterizing the extracted material. At microwave power of 540 W using 8 % NaOH for 3 min for lignin removal and 540 W for 2 min for bleaching showed the maximum yield of 37.46 %. Fourier transform infrared spectroscopy is employed to analyze the physical properties of extracted cellulose, namely the hydroxyl (OH), carbonyl (C=O), C–H bonds, C–O and C–C bonds, and glycosidic linkage (C–O–C) within the cellulose polymer chain. The extracted cellulose exhibited excellent thermal stability, as indicated by its high breakdown temperature. The X-ray diffraction (XRD) analysis revealed prominent peaks at 14.8°, 16.5°, and 22.5°, demonstrating the presence of crystalline cellulose. The crystallinity index value of 70.02 % further confirmed the crystalline nature of the extracted cellulose.