Influence of stearic acid treated nano-CaCO3 on the properties of silicone nanocomposites

The aim of the work reported here was to study the influence of treated nano-CaCO3 on the silicone:dicumyl peroxide system. Thermal degradation was studied using TGA of treated and untreated nano- and commercial CaCO3:silicone rubber composites. Thermal stability as well as % char yield increased with increasing content of treated nano-CaCO3 as compared to untreated and commercial CaCO3. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed to study the degree of dispersion of treated and untreated nano-CaCO3 and commercial CaCO3 in silicone rubber composites. Moreover, the nanocomposites were subjected to various tests, such as those for tensile strength, % elongation at break, flammability and abrasion resistance. The tensile strength (8.5 kg/cm(2)) and elongation at break (780%) showed their greatest improvements at 10 wt% loading with treated nano-CaCO3 in comparison to the untreated nano- and commercial CaCO3:silicone rubber composites. The improvements in the properties of treated CaCO3:silicone composites compared to the untreated nano- and commercial CaCO3 silicone rubber composites were due to the uniform dispersion of nanoparticles in the treated composites and their good compatibility with the rubber chains, as shown by AFM and SEM studies.