Purification, Organic Modification Of Montmorillonite And Processing Of Polycarbonate/Montmorillonite Nanocomposites

The montmorillonite containing impurities which is difficult to remove such as cristobalite was purified. The purification effectiveness of traditional centrifugal purification method and alkali extraction purification method were compared. The result shows that alkali extraction purification method is more efficiency, but the structure of montmorillonite was corroded by the sodium hydroxide solution in the purification process.Polysiloxane containing quaternary ammonium salt was synthesized by hydrosilylation reaction, then the montmorillonite was modified with it via cation exchange reaction. FTIR, X-ray diffraction (XRD), and other means of testing shows that the organo-montmorillonite was formed, the organo-montmorillonite presents excellent heat stability was proved by TGA-DSC data.The processing and preparation conditions of polycarbonate/montmorillonite nanocomposites were researched roundly, the results shows that three important factors should be considered in order to obtain intercalated even complete exfoliated structure polycarbonate/montmorillonite nanocomposites:(1)The organic modifier of montmorillonites should be compatible well with polycarbonate matrix.(2)The shear force should be large enough to ensure that favorable dispersion of montmorillonite particles.(3)With the good compatibility of montmorillonite organic modifier with polycarbonate matrix, polycarbonate/montmorillonite nanocomposites dispersion state will mainly lie on the diffusion speed of polycarbonate polymer chain.