To enhance the formation of nanocomposites, we pretreated montmorillonite clay with a high-boiling-point alcohol or a combination of the alcohol and a cationic surfactant prior to melt mixing. The polymer matrix was melt-mixed with sodium montmorillonite treated with alcohol or a combination of the alcohol and a cationic surfactant, and then, the alcohol was removed. This new method was applied to polymethyl methacrylate, polystyrene, polyethylene, and polypropylene compounds. The dual use of a surfactant and an alcohol for the treatment of montmorillonite enabled a high degree of intercalation of montmorillonite layers by polymethyl methacrylate chains, which was not obtained in untreated clay or clay treated with either the surfactant or alcohol individually. The process was not as successful with the polyhydrocarbons. There was some evidence for slightly enhanced intercalation for polystyrene, but there was less evidence for polyethylene and polypropylene. (C) 2003 Wiley Periodicals, Inc.