Nanocomposites based on natural rubber, organoclay and nano-calcium carbonate: Study on the structure, cure behavior, static and dynamic-mechanical properties

Abstract In this work, natural rubber (NR) based nanocomposites, using different amounts (0, 5, 10 and 15 parts per hundred rubber, phr) of nano-calcium carbonate (nano-CaCO 3 ) with and without organoclay (OC) are prepared by melt mixing process. The prepared samples are characterized, performing X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FE-SEM), dynamic-mechanical thermal analysis (DMTA), swelling resistance in chemicals and tensile test. The tensile test results show that by the simultaneous using of 5 phr OC and 10 phr nano-CaCo 3 the tensile strength is improved about 350%. The other tests such as XRD, FE-SEM, DMTA and swelling resistance tests as well as the theoretical investigation and calculating some thermodynamic parameters such as filler activity, activation enthalpy and Gibbs free energy reveal a considerable improvement of properties for the NR with OC and nano-CaCO 3 in comparison to corresponding nanocomposites containing either one. The optimized sample in spite of having high elasticity exhibits high loss modulus which is very important in rubber product application.