Resistance of Kapok Fibers (Ceiba pentandra) to Biotic and Abiotic Degradation: Evaluation by SEM, FTIR, Py-GC/MS, and Colorimetry

Kapok fibers (Ceiba pentandra) are considered sustainable materials, but their durabilityunder stress is poorly understood. This study examined their resistance to abiotic (UVradiation, heat) and biotic (Aspergillus niger) degradation. Fibers were exposed to 100 hof UV irradiation, 100 h of heating at 104°C, and 14 days of fungal colonization, indivi-dually and combined. Changes were analyzed with scanning electron microscopy (SEM),colorimetry, Fourier-transform infrared spectroscopy (FTIR), and pyrolysis–gas chroma-tography/mass spectrometry (Py-GC/MS). Hemicelluloses and amorphous polysacchar-ides were the most vulnerable components. UV irradiation caused yellowing, surfacecracking, and oxidative lignin modification. Heat led to moderate browning, related tosugar degradation and lignin condensation. Fungal exposure caused the most severeeffects: fiber collapse, darkening, enzymatic polysaccharide depolymerization, and ligninoxidation. Sequential stresses showed synergy: UV-pretreated fibers degraded fasterunder heat or fungal attack, accelerating polysaccharide loss and lignin disruption.Overall, kapok fibers are highly susceptible to combined abiotic and biotic stress,which compromises structural integrity and long-term durability. Protective measuresagainst UV radiation and fungal colonization are crucial for reliable industrial andenvironmental applications.