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Rubber nanocomposites based on styrene-butadiene rubber (SBR) and organophilic layered silicate were prepared. Clay structures based on dodecyl benzene sulfonic acid (DBSA), nonyl phenol ethoxylate (NPE), and DBSA/NPE (50/50%) were prepared and characterized. The results indicate the intercalation of the used surfactants within the clay layers. Varying amount of organoclay, 2, 4, 6, 8, and 10 (phr), was added to the SBR matrix. X-ray diffraction revealed exfoliated structure for the modified clay-SBR composites. No new component in the rubber was found by fourier transform infrared measurements (FTIR). Scanning electron microscopy showed a uniform distribution of the modified clay with mixed DBSA/NPE (6 phr) in the matrix. The rheometric characteristics and physicomechanical properties of the SBR compounds were analyzed. The effect of DBSA/NPE clay loading on aging resistance of SBR nanocomposites at 90 ± 1°C for 4 and 7 days was also investigated. Rubber nanocomposites displayed an increase in the minimum and maximum torques, acceleration of the vulcanization process, and improved mechanical properties, with organoclay content up to 6 phr. This effect was more noticeable in the presence of the treated clay with DBSA/NPE. Also incorporation of DBSA/NPE-clay (6 phr) resulted in significant improvement of the degradation profile of the nanocomposites at 90 ± 1°C for 4 days. POLYM. COMPOS., 36:1293-1302, 2015. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Blends containing various ratios of natural rubber (NR) and maize starch (MS) were prepared on a two roll mill. The effect of starch contents on physico-mechanical properties and curing characteristics of the prepared blend vulcanizates was investigated. The data indicate poor mechanical properties, delayed cure rate index, and decreased maximum torque with increasing starch content in the blend formulation. This indicates that the interfacial interaction between the blend components was poor. Various contents of the compatibilizers, maleic acid anhydride (MAH) and glycidyl methacrylate (GMA), were mixed with the blend NR/MS (90/10). The effect of the compatibilizer contents on the physico-mechanical properties and curing characteristics of the binary blend was investigated. Compatibilized blends with GMA (1 phr) showed an improvement in the physico-mechanical properties in comparison with uncompatibilized blend samples. Blends with MAH exhibited higher modulus and hardness values with respect to GMA blends. The efficiency of the compatibilizers was also evaluated by studies of phase morphology (scanning electron microscope), Fourier transform infrared spectroscopy, and thermal stability (thermogravimetric analysis). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]