Isolation and Characterization of Microcrystalline Cellulose (MCC) from Pineapple Leaf Fibers on Chemical, Thermal, and Morphological Properties

Microcrystalline cellulose (MCC) production from lignocellulosic biomass often involves energy-intensive and chemically harsh pretreatment methods. This study presents a resource-efficient approach to isolate MCC from pineapple leaf fiber (PALF) using a novel hand-scraping pretreatment combined with delignification, bleaching, and mild acid hydrolysis. The process increased cellulose purity from 34.37% to 93.65%, while hemicellulose and lignin were reduced to 1.06% and 0.36%, respectively. The crystallinity index increased from 21.00% to 80.10%, confirming the removal of amorphous components. FTIR analysis indicated the elimination of hemicellulose and lignin functional groups, while thermogravimetric analysis showed improved thermal stability with a maximum degradation temperature of 365.18°C. SEM results revealed a reduction in fiber diameter from 5.28 μm to 3.30 μm and a more uniform fibrillar morphology. Compared to previously reported MCC, the obtained material demonstrates high-purity cellulose, high crystallinity index, and enhanced thermal stability. These properties indicate its suitability for applications in membrane materials, filtration systems, pharmaceuticals, paper-based materials, and high-performance biocomposites.