Melt‐processable syndiotactic polystyrene/montmorillonite nanocomposites

Monoalkyl‐ and dialkyl‐imidazolium surfactants were used to prepare organically modified montmorillonites with markedly improved thermal stability in comparison with their alkyl‐ammonium equivalents (the decomposition temperatures increased by ca. 100 °C). Such an increase in the thermal stability affords the opportunity to form syndiotactic polystyrene (s‐PS)/imidazolium‐montmorillonite nanocomposites even under static melt‐intercalation conditions in the absence of high shear rates or solvents. Upon nanocomposite formation, s‐PS exhibited an improvement in the thermal stability in comparison with neat s‐PS, and the β‐crystal form of s‐PS became dominant. This crystallization response agrees with previous studies of s‐PS/pyridinium‐montmorillonite hybrids and is tentatively attributed to a heterogeneous nucleation action by the inorganic fillers. © 2003 Wiley Periodicals, Inc.* J Polym Sci Part B: Polym Phys 41: 3173–3187, 2003