Microstructure and properties of highly filled rubber/clay nanocomposites prepared by melt blending

A series of highly filled rubber/clay nanocomposites (RCNs) based on ethylene-propylene diene rubber (EPDM), styrene butadiene rubber (SBR) and epichlorohydrin rubber (ECO) were prepared by melt blending with traditional rubber processing technique. Wide-angle X-ray diffraction (WAXD) characterization shows that the highly filled RCNs (up to ∼60 wt%) have intercalated silicate structures. TEM observations reveal that the dispersion homogeneity of clay layers improves with increasing content of organically modified clay (OMC). It was shown by dynamic mechanical thermal analysis (DMTA) for the first time that the melt-like thermal transition of alkyl chains of the surfactant of OMC still occurs in the intercalated OMC. Addition of large amount OMC to rubber greatly improves the modulus of material. Highly filled RCNs also possess outstanding gas barrier properties when compared to neat rubbers.