The Effect of Organic Fillers on the Mechanical Strength of the Joint in the Adhesive Bonding

Abstract

The most important advantages of adding additives to adhesives are increasing the bonding strength and reducing the adhesive cost. The desire to reduce costs as well as the need for environmentally friendly and health-friendly products have paved the way for the recycling of waste materials and the use of cheaper natural materials as additives. In this study, mussel, olive pomace, and walnut powders in different ratios (5%, 15%, and 30% by weight) and in different sizes (38 and 45 µm) were added to an epoxy adhesive. The steel materials were joined in the form of single-lap joints by using the obtained adhesives with additives. These joints were subjected to the tensile test and the strengths of these joints were examined. SEM images of the bonding interface were taken, and the distribution of the powders was examined. When the powder size was 45 µm, bond strengths increased in all additive ratios compared to the pure adhesive, while for 38 µm powders, the strength value increased only at the 5% additive ratio. In joints with 45 µm powder additives, the strength increased by up to 38% compared to the pure adhesive, while this rate was determined as 31% for 38 µm.