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Recently PF resins can be also prepared by the addition of urea because urea accelerates cure process of PF resin, reduces the cost and improves its strength performance. Clays have long been used as inorganic fillers in polymer systems because of low cost, availability and improved thermal properties of resulting polymer composites. Clay nanocomposites of different types yield a marked increase in a number of properties of thermoplastic and other resins and composites. This study investigates the variation of thermal properties of PUF/colored organoclay nanocomposites with increased colored clay ratio. For this the DSC, XRD, FT-IR and HRTEM analyses were made. The XRD patterns and HRTEM images showed that clay platelets were exfoliated at the lower contents of organoclay, whereas at the higher content of organo clay tactoids were observed. The XRD analysis results implied that the amorphous behaviour increased with increased content of colored organoclay. The DSC thermograms indicated that glassy transition temperature (Tg) was increased, appearing prominent crystallization peaks at the lower ratios of organoclay. The Tg value was partially decreased and the peak intensities gradually decreased with increased content of clay. The thermogram for composite with clay content of 20 % was similar to the thermogram of virgin resin. This can be attributed to the shifting of the textural structure for this composite from prominent crystalline structure to amorphous one