Chemistry of Interfacial Interactions in a LDPE-Based Nanocomposite and Their Effect on the Nanoscale Hybrid Assembling

The selective solvent extraction of a LLDPE nanocomposite, prepared by using a LLDPE functionalized with maleic anhydride and an organo-modified montmorillonite (OMMT), allowed the separation of two fractions containing different contents of the starting OMMT and characterized by different morphological, dynamical, and thermal properties as revealed by WAXD, SAXS, TEM, DSC, and dielectric analysis. FTIR spectroscopy was used to confirm the degree of dispersion of the nanoparticles and to highlight the nature of chemical bonds that generate hybrid assembled structures responsible for changes in solubility, mobility, and thermal properties of the polymer chains strongly interacting with the inorganic substrate. In particular, a deconvolution procedure of the profile of carbonyl bands of functionalized polymer chains in the different fractions, together with an accurate attribution of the signals (through theoretical simulation and calculation of possible structures and their FTIR spectra), assessed the occurrence of reactions between the different functionalities of polymers and inorganic surface.