Natural rubber/nanocalcium carbonate composite was prepared by two-roll mill and compression molding. The mechanical properties of rubber composites were investigated. The variables were particle size of calcium carbonate, filler coatings and filler loading. The reinforcement by nanocalcium carbonate was compared with carbon black and silica. It was found that the curing time of coated nanocalcium carbonate rubber composite was reduced and lower than that of uncoated nanocalcium carbonate and 2u-calcium carbonate composite according to a good compatibility between the fillers and hydrophobic polymer. The modification of properties for dispersing the fillers was coating surface, which was confirmed by morphology. The cure characteristics of rubber filled with nanocalcium carbonate exhibit the lower values than that filled with silica. The mechanical properties of the coated nanocalcium carbonate exhibited the reinforcing effect while retained the elasticity of the elastomer, which is very useful for the color rubber application.
