Nanosilica-filled natural rubber composites

The dynamic viscoelastic properties of nanosilica-filled natural rubber composites was investigated. The objective of the present study was to look at the nonlinear viscoelastic behavior of natural rubber filled with commercially used nanosilica. The Payne effect is assumed to arise from the elementary mechanism consisting of adsorption-desorption of macromolecular chains from the filler surface. It was found that because of the small particle size and high specific surface area, nanosilica forms stronger and more developed filler-filler network and the breakdown of these networks results in larger Payne effect. Also, the amount and morphology of the fillers played a major role on the Payne effect. 

Figure 18.28 Thermal conductivity vs filler volume fraction for Ti02- and nanosilica-filled natural rubber (NR) composites.

The nonlinear viscoelastic behavior of the composites of natural rubber filled with surface-modified nanosilica was studied with reference to silica loading [191]. The effect of temperature on the nonlinear viscoelastic behavior has been investigated. It was observed that Payne effect becomes more pronounced at higher silica loading. The filler characteristics such as particle size, specific surface area, and the surface structural features were found to be the key parameters influencing the Payne effect. A nonlinear decrease in storage modulus with increasing strain was observed for unfilled compounds also. The results reveal that the mechanism includes the breakdown of different networks namely the filler — filler network, the... 

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