This article investigates the influence on mechanical properties of using a two compatibilizer system. Cloisite-Na Clay (ClNa) was organically modified in different ways with a polyethermonoamine and maleated polypropylene (MA-g-PP) added as a second compatibilizer. A corotating twin-screw extruder was used to obtain nanocomposites based on polypropylene via the melt intercalation technique. X-ray diffraction and differential scanning calorimetric results showed that intercalated nanocomposites with improved thermal stability were obtained. Increases of 8% in tensile strength, 34% in modulus, and 20% in crystallinity were observed. Also an increase of 23% in creep properties was observed when using these two compatibilizer system and 1% clay. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers