Effect of methyl orange as the modifier on the mechanical, thermal, and thermo-mechanical properties of clay/epoxy composites
Abstract
In this study, bentonite clay/epoxy composites were simply and successfully produced via conventional casting method for 0.5, 1, and 2 wt% filler content. Previously modified clay (surfactant and silane agent applied) was treated with methyl orange (MO) and its effects on composites were investigated in terms of crystallographic, thermal, thermo-mechanical, morphologic, and topographic aspects as well as quasi-static characteristics. According to XRD graphs, MO presence led to the increase of interlayer distance and resulted in partial intercalation for modified clay (MC) based mixture, while an opposite case was seen in neat clay (NC) blend. The 2 wt% MO/MC loaded composite achieved the highest tensile modulus, flexural stiffness, and hardness values among all samples-increase of 14%, 40%, and 3%, respectively. Same composite system exhibited improved results for both glass transition temperature (similar to 7%up arrow) and storage modulus (similar to 35%up arrow), in spite of insufficient thermal characteristics. Irregular particles/tactoids were present in the fracture images, which probably promoted the stress concentration and caused the reduction of strength parameter for all composites. Furthermore, independent of clay type (MC or NC) whole structures showed similar surface roughness values but different topographic textures in terms of surface profiles.