Structural design of imidazolium and its application in PP/montmorillonite nanocomposites

Four kinds of imidazolium surfactants with high thermal stability were designed and synthesized accordingly. The structures of these surfactants were characterized by 1H NMR spectra. The TGA results indicated that the thermal stabilities of these surfactants with saturated alkyl groups were relatively high and the initial decomposition temperatures at 5% weight loss (T0.05) were higher than 250 °C. Imidazolium(O) modified montmorillonite (MMT) was prepared by cation exchange. TGA results showed that the OMMT showed obviously higher thermal stability than the surfactants themselves and the T0.05 values of OMMT were higher than 330 °C. The dihexadecane imidazolium (DHI) with two long tails has the ability to enlarge the interlayer spacing to a bigger degree compared with other imidazolium surfactants with only one long tail. Polypropylene(PP)/OMMT nanocomposites were prepared by solution blending and the effects of these surfactants with different structures on the silicate layer dispersion in PP matrix were measured.