Preparation, characterization, and thermal properties of polystyrene‐<i>block</i>‐quaternized poly(4‐vinylpyridine)/Montmorillonite nanocomposites

Abstract

Abstract Polystyrene‐ block ‐poly(4‐vinylpyridine) (PS‐ b ‐P4VP) was synthesized by two steps of reversible addition‐fragmentation transfer (RAFT) polymerization of styrene (St) and 4‐vinylpyridine (4VP) successively. After P4VP block was quaternized with CH 3 I, PS‐ b ‐quaternized P4VP/montmorillonite (PS‐ b ‐QP4VP/MMT) nanocomposites were prepared by cationic exchange reactions of quaternary ammonium ion in the PS‐ b ‐QP4VP with ions in MMT. The results obtained from X‐ray diffraction (XRD) and transmission electron microscopy (TEM) images demonstrate that the block copolymer/MMT nanocomposites are of intercalated and exfoliated structures, and also a small amount of silicates' layers remained in the original structure; differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results show that the nanocomposites displayed higher glass transition temperature ( T g ) and higher thermal stability than that of the corresponding copolymers. The blending of PS‐ b ‐QP4VP/MMT with commercial PS makes MMT to be further separated, and the MMT was homogeneously dispersed in the polymer matrix. The enhancement of thermal stability of PS/PS‐ b ‐QP4VP/MMT is about 20°C in comparison with commercial PS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1950–1958, 2006