No abstract

The chemical, morphological, physical, and thermal properties of raw materials and single fibers extracted from different morphological parts of windmill palm were examined and comprehensively characterized after an alkali treatment. Leaf sheathes (LS) with the highest cellulose content (52.26%) achieved the most efficient extraction of fibers. Single fibers extracted from the vascular bundles of the windmill palm raw material had a slender shape with a tapering and sealing terminus, with each single fiber possessing a lumen in its cross-section. These windmill palm fibers displayed similar chemical compositions, but they exhibited significant differences in morphological parameters. Leaf blade fibers (LBFs) had the longest length (1240 μm ± 470 μm) and highest aspect ratio (121.39), which presented excellent potential as a reinforced fiber. After the alkali treatment, almost all of the hemicelluloses and lignin were removed, which resulted in increased crystallinity of extracted fibers. Thermogravimetric analysis confirmed LS stability up to 319 °C, which was higher than that of other materials from windmill palm.

In this work, windmill palm fiber (WPF), alkali-treated fiber (AF) without hemicellulose and bleached fiber (BF) without lignin were prepared and buried in soil for 30, 60 and 90 days. The surface morphology, chemical composition, crystallinity degree, mechanical properties, and residual mass rate of the samples, before and after biodegradation, were investigated. According to the results, soil burial degradation can remove the parenchyma cells and silica-bodies of WPF and deplete droplets containing the lignin of alkali-treated fiber after it has been buried for 30 days (AF30), and degradation of the single fiber cell wall of bleached fiber after it has been buried for 30 days (BF30). Buried in natural soil, lignin has a slower degradation rate than that of hemicellulose. WPF showed no significant differences in tensile strength after burial in soil for 90 days, because of the integrity fiber structure decreased the biodegradation. The most serious decrease, about 43%, in tensile strength occurred in AF after it had been buried for 90 days (BF90). This basic knowledge may be helpful for windmill palm fiber applications, especially for biodegradable composites.

No abstract