Highly thermal stable organoclays of ionic liquids and silane organic modifiers and effect of montmorillonite source

Since many polymer–organoclays nanocomposites are prepared in melt state, the thermal stability of the surfactants present in these organoclays is extremely important. Alkyl ammonium salts are surfactants which have been used in organoclays, but the low thermal degradation temperature of these salts is a drawback for polymer nanocomposites preparation in the melt state at temperatures higher than 200 °C. In order to obtain organoclays more suitable to be used in these polymer nanocomposites, in this work clay minerals were modified with more thermally stable organic modifiers than conventional salts. Two types of commercial clay minerals were organically modified with alkyl ammonium salt, alkyl and aryl phosphonium salts and an organosilane compound. X-ray diffraction, thermogravimetric analysis (TG) and infrared analysis results indicate that for both commercial clay minerals the preparation of the organoclays was efficient. TG analysis confirmed that phosphonium and silane organoclays are more thermally stable as compared with conventional alkyl ammonium organoclays. It was also observed that the thermal resistance of the organoclay depends on the type of the aluminosilicate used for the organic modification.