Effect of sequential alkali–acid treatment on pineapple leaf fiber properties
摘要
This research examines the impact of chemical treatments, particularly sodium hydroxide (NaOH) and hydrochloric acid (HCl), on the structural and thermal properties of Pineapple Leaf Fibers (PALF) utilized in bio-composite reinforcement. Fibers, with sizes 25–150 μm and 150–300 μm, are examined through FTIR, DSC, XRD, TGA and SEM. FTIR analysis shows the removal of hemicellulose and lignin and OH stretching bands shifting to 3668–3370 cm−1. TGA analysis indicates improved thermal stability, as breakdown peaks shifted from ~ 200 °C in untreated fibers to > 345 °C in treated fibers with higher residues. DSC exhibits a melting transition at 345.26 °C and glass transition at 138.98 °C. XRD measurement indicates improved crystallinity with dominant 200 peaks consistently observed at ~ 22°–23° for both 25–150 μm and 150–300 μm fibers, respectively and crystallinity index increasing up to 86.90%, confirming enhanced cellulose ordering after sequential treatment. The SEM analysis shows higher surface roughness and fibrillation. The 25–150 μm fibers possess a higher degree of structural ordering, which make them suitable for high-performance thermal and structural composite uses.
Graphical abstract