Effects Of Modification Ways On The Properties Of Modified Montmorillonite And Its Polypropylene Composites

A series of imidazolium ionic liquids were synthesized as modifier of montmorillonite (MMT), which have strong interactions between montmorillonite layers and high thermal stability. Effects of modification ways on the properties of modified montmorillonite and its polypropylene composites were studied. The effects of absorption style and state of imidazolium cations on the process of polypropylene intercalation into the interlayer of MMT have also been discussed.Imidazolium ionic liquids with hydroxyl group or double bonds, as well as that with long alkyl group were synthesized. Imdazolium cation/montmorillonite hybrids were prepared via ion-exchanging reaction in water and toluene.The structure and properties of ionic liquid modified MMT (O-MMT) were investigated by wide-angle X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). On the basis of TGA data, relationship between the amounts of ionic liquid loaded and the amounts of organic ions adsorbed in the interlayer of O-MMT was analyzed. With the increasing amount of absorbed imidazolium cations in the interlayer of montmorillonite, the aggregate structures of imidazolium cations become more ordered, and leading to an obvious increasing of the interlayer distance of MMT.The XRD and TGA results showed that the polarity of solvent have an effect on the absorption state of organic cation in the interlayer of MMT, the model of absorption process and its state has been put forward too.Based on the study of the structure and properties of imdazolium cation /montmorillonite hybrids, one kind of imdazolium ionic liquid was used to organically modify montmorillonite, and then the PP/montmorillonite composite was prepared by solution blending. Thermal properties, mechanical properties and dynamic mechanical properties of the composite were improved optically.Montmorillonite was modified by mechanical chemistry, using one kind of ionic liquid as modifier, and then PP/montmorillonite composite prepared by melt blending. Testing results show this composite have higher thermal stability and mechanical properties.Effects of absorption style and state of imidazolium cations on the process of polypropylene intercalation into the interlayer of MMT have also been studied. Results show that the PP chain grafted maleic anhydride could be intercalated into the interlayer of MMT easily and get partly exfoliated PP/MMT nanocomposites when the O-MMT have larger interlayer distance and there are active sites in the interlayer of O-MMT.