Study on structural and thermal properties of cellulose microfibers isolated from pineapple leaves using steam explosion

In Thailand, pineapple leaves are one of the most common agricultural wastes after cultivation. The aim of this research was to understand effects of the steam explosion treatment conditions (steam pressure and treatment cycle) on properties of cellulose microfibers extracted from pineapple leaves. The fibers were steam exploded at pressure of 16 and 20 kgf cm−2 between 1 and 5 cycles. The steam explosion technique could partially eliminate hemicellulose and lignin and increase the cellulose content, leading to improvement of the thermal properties and crystallinity of the treated fibers. With increasing the steam pressure and treatment cycles, changes of the fiber morphology were observed. Smaller widths and shorter lengths of the treated fibers could be obtained. Microfibers with widths of 3 μm and lengths of 93 μm were extracted from fiber bundles with widths of 45.8 μm and lengths of ∼2 cm with the pressure of 20 kgf cm−2 for 5 cycles. Also, the steam explosion method could possibly fibrillate cellulose nanofibers. With more cycles of the steam explosion treatment, large amounts of cellulose nanofibers could be found.