Effect of extraction method on the tensile properties of date palm fibers and their adhesion to thermoset resins

This study evaluates the tensile properties and interfacial shear strength (IFSS) of date palm fibers extracted from midrib (M) and spadix stem (S) components when bonded with epoxy, polyester, and phenolic resol resins. Fibers were extracted using three treatment methods: (1) boiling in distilled water for 1 h, (2) 1% NaOH immersion for 24 h, and (3) 1% NaOH immersion for 48 h. Results demonstrated significant effects of resin type and extraction duration on interfacial performance. Epoxy resin exhibited superior adhesion, achieving 49 MPa IFSS with 48-h-treated M fibers, whereas S fibers under identical conditions reached 10.2 MPa. Prolonged extraction reduced fiber cross-sectional area but enhanced interfacial bonding. Critical fiber length analysis revealed a maximum value of 13.22 mm for S fibers with resol resin. Scanning electron microscopy (SEM) characterized surface morphological changes induced by treatments. The findings position these fibers as viable reinforcements for polymer composites in automotive (e.g., door panels), construction (e.g., lightweight partitions), and packaging applications, offering both agricultural waste valorization and sustainable material development.