In this study, styrene butadiene rubber (SBR)/organoclay nanocomposites were manufactured using the latex method with 3-aminopropyltriethoxysilane (APTES) and N,N-dimethyldodecylamine (DDA) as modifiers. The layer-to-layer distance of the silicates was observed according to each manufacturing process for APTES as the modifier using the X-ray diffraction (XRD) method. From the XRD results and the TEM images, the dispersion of the silicates impoved for both APTES-MMT and DDA-MMT, and the dispersion of the silicates with the DDA modifier improved more than the APTES modifier. The SBR/DDA-MMT compound exhibited the fastest scorch time, optimal vulcanization time, and cure rate. The dynamic viscoelastic properties of the SBR/APTES-MMT compound were measured according to the change in the strain amplitude in order determine if a covalent bond was formed between APTES and bis(triethoxysilyl-propyl)tetrasulfide (TESPT). The mechanical properties of the SBR/DDA-MMT nanocomposite improved more than the SBR/APTES-MMT composite because the vulcanization effects of alkylamine and the dispersion of silicates within the rubber matrix were relatively good. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 3373-3387, 2010