ABSTRACT
Numerous studies have investigated the material properties of clay/polymer nanocomposites, such as their fracture toughness, elastic modulus, and hardness. However, only a few researchers have studied the tribological properties of clay/polymer nanocomposites. This study investigated the effect of the montmorillonite (MMT) concentration on the tribological behavior of MMT/epoxy nanocomposites. Wear tests were performed on MMT/epoxy nanocomposites with four different clay concentration levels to characterize the improvement in wear behavior due to the MMT concentration. In order to examine the tribological mechanism depending on the clay concentration level, SEM analysis was performed on the worn surfaces after the wear tests. The results showed that the friction coefficient of an MMT/epoxy nanocomposite with a low MMT concentration was larger than that of a nanocomposite with a high MMT concentration. It is believed that the phenomena occur due to the action of MMT as a reinforcement and lubricant material and reduce the wear rate with increasing MMT concentration.
ABSTRACT
Residual strength tests were performed on unmodified and silane-modified clay/epoxy nanocomposites by applying various cyclic stresses. The residual strength of silane-modified samples proved to be greater than that of unmodified samples, irrespective of the cyclic stress level. For clay/epoxy nanocomposites, cyclic stress proved to have little effect on residual strength. Fatigue strain energy was improved by the silane modification of clays because of an increase in the toughness and interfacial strength between the clays and epoxy matrix.
ABSTRACT
It is known that the mechanical properties of clay-reinforced nanocomposites are significantly affected by the dispersion of clay particles in the matrix. In this study, the effect of surface-treatment of Montmorillonite (MMT) on the fracture behavior of MMT/epoxy nanocomposite was investigated. For this purpose, fracture tests were performed using samples with three different clay concentration level. After fracture tests, SEM analysis was made on the fracture surfaces to examine the fracture mechanism. It was found that the MMT treatment using 3-aminopropyltriethoxysilane enhanced the fracture toughness increased of the MMT/epoxy nanocomposite. This is due to the improved intercalation effect and interfacial strength between MMT and epoxy matrix.
