Influence of Date Palm Tree Fibers on the Tensile Fracture Energy of an Epoxy-based Adhesive

Abstract

ABSTRACT In the previous study, the effect of date palm fibers on the shear strength of adhesively bonded joints has been investigated by the same authors. Nevertheless, the role of these bio-based fibers on the fracture energy of adhesives has not been explored. The current study was conducted to comprehend the influences of date palm fibers on mode I fracture energy (GIc ) of adhesives. To this aim, the fibers were collected from four different parts of a date palm tree (Bunch, Rachis, Petiole, and Mesh). After an alkalization treatment, they were cut into 0.5 to 2 mm and added to the adhesive in three various weight ratios (2, 5, and 10%). The fracture energy of the neat and reinforced adhesively bonded double cantilever beam (DCB) was then experimentally analyzed utilizing a compliance-based method. The outcomes prove the outstanding potential of the date palm fibers in enhancing the tensile fracture energy of adhesives. The highest improvement in GIc was achieved by 10 wt% Rachis fibers where the fracture energy of the enhanced adhesive was 7.6 times higher than the neat adhesive. The microscopic images of fracture surfaces revealed the significant roles of the considered fibers in the improvement of the GIc of the adhesive.