Preparation and Characterization of PMMA/Montmorillonite Nanocomposite by Emulsion Polymerization

Sodium silicate is used to passivate sodium base montmorillonite(MMT).Moderating the pH value of the system and function of polymerization anions endows MMT with negative charges and controls the dispersion of MMT in water,thus making the exchange reaction of MMT and organic cation complete.Amount of cation exchange of the resultant organo-MMT is up to 115 mmol/100g MMT.It can disperse in MMA evenly.By means of emulsion polymerization, PMMA/organo-MMT nanocomposite was prepared.The composite is extracted by toluene and characterized by FTIR,XRD,TEM,DSC and TGA.Results showed that nano dispersion of organo-MMT in PMMA was achieved and most of it was exfoliated.Thermal performance of the composite was improved greatly compared to pure PMMA.Its glass-transition temperature and degradation temperature reached 30.61 ℃ and 42.13 ℃ respectively.