The Comparison of Organoclay with Respect to Silica on Properties of Natural Rubber Nanocomposites

Effects of organoclay loading (organophilic modified montmorillonite with octadecylamine) in comparison to silica loading on the curing characteristics, tensile properties, thermal stability, and morphology of natural rubber (NR) nanocomposites were studied. Organoclay loading from 2 to 10 phr and silica with 10 and 30 phr loading were used as fillers in this study. The NR/organoclay nanocomposites were compounded using two roll mills and cured at 150°C. The results indicate that the tensile strength and tensile modulus reach maximum at 8 phr of organoclay but elongation at break and thermal stability increase with increasing organoclay loading. Tensile strength, tensile modulus, and elongation at break increase with increasing amount of silica from 10 to 30 phr. Overall results show that organoclay filled NR nanocomposites exhibit shorter processing time and higher tensile properties than silica filled NR nanocomposites. The enhanced properties are due to the homogenous dispersion of individual silicate layers in NR matrix, which is evidenced from the X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) results.