Thermally stable phosphonium-montmorillonite organoclays

Sodium montmorillonite (MMT) was modified with several organic phosphonium salts. Organoclays with water soluble surfactants were prepared by the traditional cation exchange reaction. An alternative procedure was used to prepare organoclays with water insoluble salts. The effect of chemical composition and molecular weight of the salts on the thermal stability and basal spacing were evaluated. The phosphonium montmorillonites exhibit higher thermal stability than conventional ammonium organoclays. The basal spacing is generally larger for the phosphonium montmorillonites. These properties provide a good potential for the use of phosphonium organoclays for the synthesis of polymer/clay nanocomposites by melt processing.