Experimental study on interfacial shear strength between date palm fibers and thermoset resins

Abstract

Date palm fibers (DPFs) can be potentially used in novel applications including composites. In this study, the Microbond technique was used to measure the interfacial shear strength (IFSS) between DPFs extracted from the mesh (ME), the midrib (MI), and the Spadix stem (SS) and three types of thermoset resins, i.e., unsaturated polyester (P), epoxy (E), and phenolic Resol (R). The fibers’ tensile strength was measured and the aspect ratio of the fibers (critical length/diameter) for different fiber-resin systems was determined. It was shown that there is a clear relationship between resin droplet contact angle and IFSS. SS fibers provided the highest and ME fibers the lowest IFSS values among the fibers. Among the resins, E provided the highest and R the lowest adhesion to all fibers. The IFSS values of the E with MI, SS, and ME fibers were 7.62, 8.89, and 5.88 MPa, for the R matrix were 2.94, 3.02, and 2.33 MPa, and for the P matrix were 5.59, 5.97 and 5.17 MPa, respectively. It was shown that there is a clear relationship between IFSS values and contact angles of different fiber/matrix systems.