Morphology and Properties of NR/EPDM Rubber Blends Filled With Small Amounts of Titania Nanoparticles

This article describes the results of an investigation on the influence of titania nanoparticles on the morphology and properties of vulcanized natural rubber (NR)/ethylene-propylene-diene monomer (EPDM) blends. The samples were prepared through roll-milling and melt-pressing and diphenyl guianidine was used as vulcanization accelerator. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) results show that the titania particles are concentrated in the NR phase, and that the presence of titania in EPDM seems to initiate the formation of crystals in the rubber phase. From the dynamic mechanical analysis (DMA) and tensile testing results it is clear that the presence of titania particles inhibited the vulcanization process in both the investigated rubbers, and that the mechanical properties of the nanocomposites were influenced by the interaction between the nanoparticles and the rubber, the reduced vulcanization of the two rubber phases, and the development of crystallinity in EPDM. The thermogravimetric (TGA) results show improved thermal stability of EPDM, and of the EPDM phase in the blend, for the samples containing titania nanoparticies. POLYM. COMPOS., 32:1289-1296, 2011. (C) 2011 Society of Plastics Engineers