Dynamic Properties of Star-Shaped, Solution-Polymerized Styrene-Butadiene Rubber and Its Cocoagulated Rubber-Filled with Silica/Carbon Black

The dynamic properties, including the dynamic mechanical properties, flex fatigue properties, dynamic compression properties, and rolling loss properties, of star-shaped solution-polymerized styrene-butadiene rubber (SSBR) and organically modified nanosilica powder/star-shaped styrene-butadiene rubber cocoagulated rubber (N-SSBR), both filled with silica/carbon black (CB), were studied. N-SSBR was characterized by H-1-NMR, gel permeation chromatography, energy dispersive spectrometry, and transmission electron microscopy. The results show that the silica particles were homogeneously dispersed in the N-SSBR matrix. In addition, the N-SSBR/SiO2/CB-rubber compounds' high bound rubber contents implied good filler-polymer interactions. Compared with SSBR filled with silica/CB, the N-SSBR filled with these fillers exhibited better flex fatigue resistance and a lower Payne effect, internal friction loss, compression permanent set, compression heat buildup, and power loss. The nanocomposites with excellent flex fatigue resistance showed several characteristics of branched, thick, rough, homogeneously distributed cross-sectional cracks, tortuous flex crack paths, few stress concentration points, and obscure interfaces with the matrix. Accordingly, N-SSBR would be an ideal matrix for applications in the tread of green tires. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40348.