Thermal stability rubber-clay nanocomposites

In rubber-plastic blends, clay reportedly disrupted the ordered crystallization of isotactic polypropylene (iPP) and had a key role in shaping the distribution of iPP and ethylene propylene rubber (EPR) phases larger filler contents brought about smaller, less coalesced and more homogeneous rubber domains [22]. Clays, by virtue of their selective residence in the continuous phase and not in the rubber domains, exhibited a significant effect on mechanical properties by controlling the size of rubber domains in the heterophasic matrix. This resulted in nanocomposites with increased stiffness, impact strength, and thermal stability. 

The addition of nanoparticles to synthetic rubber resulting in enhancement in thermal, stiffness and resistance to fracture is one of the most important phenomena in material science technology. The commonly used white filler in mbber industry are clay and silica. The polymer/clay nanocomposites offer enhanced thermo mechanical properties. Bourbigot et al. observed that the thermal stability of polystyrene (PS) is significandy increased in presence of nanoclay [75]. Thermal and mechanical properties of clays multiwalled carbon nanotubes reinforced ethylene vinyl acetate (EVA) prepared through melt blending showed synergistic effect in properties [76]. 

Kong et al. [115] synthesized hy melt-intercalation silicone rubber (SR)/clay nanocomposites using synthetic Fe-montmoriUonite (Fe-MMT) and natural Na-MMT which were modified by cetyltrimethylammoniumbromide, surfactant. They obtained exfoliated and intercalated nanocomposites. With TGA and mechanical performance found that with the presence of iron significantiy increased the onset temperarnre of thermal degradation in SR/Fe-MMT nanocomposites. In addition, the thermal stability, gel fraction and mechanical property of SR/Fe-MMT were different from the SR/Na-MMT nanocomposites, so the iron not only in thermal degradation but also in the vulcanization process acted as an antioxidant and radicals trap. A new flame-retardant system, SR/Fe-OMT based on an EVA matrix, was examined Fang et al. [ 116]. The experimental analyses showed that the exfoliated Fe-OMT had better dispersion in the EVA matrix than Na-OMT, and it was more effective in improving... 

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