Modification of montmorillonite by different surfactants and its use for the preparation of polyphenylene sulfide nanocomposites

Polyphenylene sulfide (PPS)/clay composites were prepared by simple melt blending. Three different kinds of surfactants such as cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl benzene sulfonate (SDBS), and synthetic 1,3-dihexadecyl-3H-benzimidazolium bromide (Bz) were used as organic modifiers for the organic modification process. The benzimidazolium-modified montmorillonite (Bz-MMT) and CTAB-modified MMT (CTAB-MMT) exhibited larger interlayer spacing than SDBS-modified MMT (SDBS-MMT), while SDBS-MMT and Bz-MMT exhibited higher thermal stability compared with the CTAB-MMT. The morphology of the PPS/organic MMT nanocomposites was evaluated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The nanocomposites based on SDBS-MMT and Bz-MMT exhibited good overall dispersion of organic MMT with a mixed dispersion of intercalated and exfoliated structures. Differential scanning calorimetry and thermogravimetric analysis (TGA) were used to evaluate the thermal properties of PPS/organic MMT nanocomposites. The crystallization process of PPS in all nanocomposites was accelerated, and the crystallinity also increased, when compared with the pure PPS from the DSC analysis. The TGA analysis indicated that nanocomposites based on SDBS-MMT and Bz-MMT exhibited higher thermal stability than composites based on CTAB-MMT due to the well-dispersed nanoplatelets.