Experimental evidences of polymer confinement and its effect in gas barrier properties in polyolefins/MMT nanocomposites

Polyolefins/MMT nanocomposites with exfoliated, intercalated and mixed morphology were prepared by melt blending EPM and LDPE containing a moderate amount (0.08÷1.8 by mol) of grafted diethylsuccinate or succinic anhydride groups. Material characterization by DSC, x-ray diffraction, TEM microscopy, FT-IR, dielectric spectroscopy and extraction with hot toluene allowed to demonstrate the existence of strong interactions at the polymer/MMT interface through the polar groups grafted to the polyolefin. Nanocomposite permeability to oxygen and water vapour was discussed with reference to the above mentioned interface interactions.