Nanocomposites containing Epoxidized Natural Rubber (ENR) and organoclay via solution intercalation under vigorous stirring have been prepared. The nanoclay employed in this study is Cloisite 20A and the solvent used to dissolve ENR is toluene. Nanocomposites contains 50 wt% of organoclays dispersed in ENR. The 5 and 10 phr of the obtained ENR/organoclay nanocomposites is incorporated in the Natural Rubber (NR) matrix, along with Carbon Black (CB) and sulphur as a curing agent. Morphology, curing characteristics and mechanical properties of the nanocomposites were determined and discussed. X-Ray Diffraction (XRD) peaks denote that the clay is highly intercalated in ENR and Transmission Electron Microscopy (TEM) images show higher intercalation and partial exfoliation of the nanoclay in ENR. Compound containing 5 phr of ENR/nanoclay composites in NR matrix shows maximum torque, faster cure rate and increased cross-link density. The overall mechanical properties are also increased for this particular compound. The compound containing 10 phr of ENR/nanoclay composites in NR matrix exhibits further enhancement in modulus, hardness and gives lesser wear loss.

Substantially around 1,000 articles have been reported in the literature dealing with the preparation, morphology and properties of organoclay nanocomposites for the past decade.^* The reinforcement of the organoclay in the polymer matrix is very high due to their nanometer phase dimensions, which indeed generate very large surface areas. Hence it exhibits substantial improvements in the physical, mechanical and thermal properties in relation to the polymer host [1-3]. Immense work has been done on clay nanocomposites for many thermoplastics and thermosetting polymers. However, the studies on rubber-based nanocomposites constitute in lesser dimension [3, 4-6].

Recently Mohamed and Simon [7]; and Utraki [8] reported the most significant advances in the organoclay/rubber nanocomposites based on several rubber matrices. The elastomers selected in this study were Natural Rubber (NR) and Epoxidized Natural Rubber (ENR). NR exposes excellent physical and mechanical properties due to its ability to crystallize under stretching. ENR is obtained by the epoxidation of 1, 4-polyisoprene, which depicts a higher glass transition temperature and increased polarity, than that of pure NR. Organoclay can be more easily dispersed in polar polymers than in non-polar polymers. Accordingly, as a fine dispersion of organoclay is expected, the ENR which depicts high polarity has been chosen. As NR is not polar, to improve the dispersion of nanoclay, polar ENR is used as a compatibilizer in the nanocomposite preparation.

Effect of Epoxidized Natural Rubber, ENR, Natural Rubber matrix, NR, Carbon Black, Transmission Electron Microscopy, TEM, X-Ray Diffraction, XRD, Agricultural Product Processing Research Institute, Dynamic Mechanical Thermal Analysis, Scanning Electron Microscopy, Cure rate index, Morphology, Organo-montmorillonite.