dried at 25 ?C for 1 week). the XRD patterns for the samples with different OMMT content (wt%). the marked diffraction peaks of OMMT were not observed for the samples with a OMMT content of 1 and 3wt% which indicates the formation of more exfoliated structure in these samples. On the other hand, a weak diffraction peak was observed for the other samples with OMMT content of 5 wt%, which reveals that the layered OMMT was not entirely exfoliated, that is, a mixture of exfoliated structures is revealed. Effect of this structural feature on the free volume and the mechanical properties is very important. The chemical and physical interactions between ingredients in composites play an important role in the improvement of service properties. IR spectroscopy was also adopted to examine the intermolecular hydrogen bonding of epoxy resin with nano particles as well as intramolecular one within polymer matrix. The vibration frequency of hydroxyl group (-OH), benzene ring and ester group shifts from 3542 to 3535 cm -1 ,1616 to 1612 cm -1 and 1040 to 1032cm -1 , respectively. Measurments of mechanical properties of the nanocomposite samples indicated that the sample containing 3 wt% nano particles could be selected for the highest properties. These samples showed 125.7% and 400% increase in adhesion strength and impact strength respectively and 57.1% increase in abrasion resistance compared with the reference sample. Measurments of mechanical properties and corrosion resistance of the paint samples indicated that the sample containing 3 wt% nano particles could be selected for the highest properties. These samples showed 144% and 350% increase in adhesion strength and impact strength respectively and 57.1% increase in abrasion resistance compared with the reference sample. Anti-corrosive properties of the nanocomposite were investigated using salt spray method. The results showed an improvement in the barrier and anti-corrosive characteristics of epoxy-based nanocomposite coating and a decrease in water uptake in comparison with pure epoxy coating. The salt spray test of these samples was carried out for 1250h without any sign of the steel corrosion. The reference samples (without nano particles) showed steel corrosion at 750h in salt spray test.