Combined effect of nano-clay and nano-carbon black on properties of NR nanocomposites

Natural rubber (NR)/clay/carbon black nanocomposites, filled with 10 phr, 20 phr, and 30 phr of filler (in total) were obtained by adding carbon black (N330) on a two-roll mill to NR/clay nano-compounds prepared by the emulsion compounding method. X-ray diffraction patterns and transmission electron microscope photographs of the nanocomposites showed that both fillers were dispersed randomly in the NR matrix at nano-scale and that the space between the clay layers was filled with carbon black particles. At the same total filler loadings, the mechanical properties of the naocomposites filled with both clay and carbon black, such as moduli at 100% and 300% elongation, tensile strength and tear strength, were greatly improved compared with those of either NR/clay nanocomposites or NR/carbon black nanocomposites. This indicates that the samples with both fillers possessed excellent mechanical properties. It was found that the NR/clay/carbon black nanocomposites retained advantages from both fillers, for example, the processability and dynamic properties were close to those of NR/carbon black nanocomposites, and the gas barrier properties were almost as good as those of NR/clay nanocomposites.