Comparing the Reinforcing Performance of nano-CaCO3 in Natural Rubber and Nitrile Rubber

Better understand the mechanism of reinforcing produced by spherical nanoparticles in this rubber will help significantly in achieving engineering products. In this paper, the effect of nano-calcium carbonate was investigated in the range 0-20 phr on the properties of natural rubber (NR) and nitrile rubber (NBR) including cure rheometry (scorch time, cure time, max and min torque and different torque), tensile behavior, hardness and swelling resistance. Various experimental results show that changes many properties by addition of nano-CaCO3 are quite similar in the two rubbers and the optimal amount of nano-CaCO3 in both rubbers is 15 phr which by higher content, will be loss mechanical properties as well as other engineering properties. Significant improvement in mechanical properties without reducing the elastic properties of the rubber compounds is reason of the effectiveness of the enhanced mechanical properties of used nanoparticles in this study. Effect of calcium carbonate nanoparticles in change of Gibbs free energy is remarkable in natural rubber and reflects the greater tendency of solvent to natural rubber than nitrile rubber. Better dispersion of nanoparticles of calcium carbonate in nitrile rubber and also stronger interactions in interface of nano-CaCO3 and nitrile rubber with Kraus plotting was concluded.