Development of an epoxy based intumescent system comprising of nanoclays blended with appropriate formulating agents

A novel intumescent coating technology for metallic surfaces was developed using functionalized clays, which were intercalated and exfoliated into nanodimensions. The nanoclays were formulated in epoxy resins and blended with appropriate additives to design intumescent coatings for metallic surfaces. With the high dispersion of nanoclay the flame retardancy is improved. The extent and the homogeneity of the exfoliation and dispersion of the clay particles were assessed employing small-amplitude oscillatory shear. The performance and properties of the coatings were evaluated by means of fire resistance testing, thermo-gravimetric analysis and mechanical properties. The incorporation of the nanoclays significantly increased the elasticity and the viscosity of the intumescent formulations and improved the fire resistance of the epoxy coatings. It is observed that significant gains in flame retarding properties could be achieved when the clay platelets could be adequately exfoliated and dispersed.