Interlamellar Incorporation of Charged Polymer Nanobeads into Sodium Montmorillonite

摘要

Complete delamination of clay in polymer matrix has been strongly prohibited due to strong adhesion of guest polymer chains between hydrophilic clay as well as degradation and desorption of organic materials in the gallery at high temperature.Incorporation of charged nano-sized polystyrene beads directly into the gallery of pristine clay through exfoliation-exchange mechanism has been proposed to overcome the drawbacks.Synthesis of polymer nanobeads via emulsifier-free emulsion polymerization allowed to achieving formation of particles of appropriate particle size and surface charge density.Surface characterization,performed with XPS and ToF SIMS,has provided the results on the existence and the nature of the functional groups on the polymer particle surface,which have been found to be in a good compliance.Morphology of polymer-incorporated clay was observed from TEM,FE-SEM images.Study on mechanism of incorporation via XRD,XPS,ToF-SIMS suggested that adsorption of polymer nanobeads through cationic exchange of intergallery cation of clay for onium ion at the surface of polymer nanobead not only improves compatibility of clay with polymer matrix,but,what is essential,dramatically promotes expansion of clay gallery.