Preparation and characterization of novel nanocomposites based on polyacrylonitrile/kaolinite

A novel intercalation nanocomposite based on polyacrylonitrile (PAN)/kaolinite was prepared by a simple in situ emulsion polymerization in the presence of organically modified layered silicates (kaolinite). The crude kaolinite (K₀) was firstly modified by dimethylsulfoxide-methanol and potassium acetate-aqueous systems; acrylonitrile monomer was then intercalated into kaolinite by displacing potassium acetate from KAc-kaolinite (the kaolinite modified by KAc, marked as K₂). The polymer/kaolinite composites were prepared by in situ emulsion polymerization, and characterized by means of X-ray diffraction, scanning electron microscope, transmission electron microscope and thermal gravimetric analysis. Experimental results indicate that the clay layers of kaolinite in PAN/K₂ composites are well distributed and delaminated. The weight-average molecular weights were measured by small-angle X-ray scattering for all samples. The presence of clay results in an increase in molecular weights compared to pure PAN polymer due to the highly crosslinked structure.