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Low-density polyethylene/layered double hydroxide (LDPE/LDH) nanocomposites were prepared via melt extrusion using organo-LDH particles and maleic anhydride functionalized polyethylene as compatibilizer. Processing parameters, preparation method, and feed composition were properly modulated until obtaining nanocomposites with intercalated/exfoliated morphologies, and an uniform distribution of nanolayers, as evidenced by X-ray diffraction and transmission electron microscopy analysis. These materials showed a significant improvement of the thermal-oxidative stability, which increased of about 50-C during the first step of the degradation process. Moreover, a remarkable reduction of the oxygen permeability, proportional to the aspect ratio of LDH stacks dispersed in the polyolefin matrix was evidenced, indicating the possible application of nanocomposite films as food packaging materials. As highlighted by dynamic mechanical thermal analysis, interactions at the interface between LDH layers and polymer chains caused a shift of the LDPE b-relaxation toward higher temperatures and a reduction of the peak intensity with respect to the matrix. It was also found that the storage modulus of the nanocomposites was lower in all the temperature range with respect to the reference samples. Finally, on-line capillary rheometer measurements evidenced that the shear thinning behavior of the nanocomposites was dominated by the matrix so that the melt processability was not compromised by the presence of the filler.

The performances of vulcanized SBR-based compounds containing Cloisite 30B modified with maleinized polybutadienes are correlated with the degree of clay delamination observed by TEM. Moreover, new organo-modified clays bearing one hydroxyl group and characterized by high interlamellar distance were prepared, characterized and used for the preparation of technical compounds.

An efficient approach to the organic functionalization of multiwalled carbon nanotubes (MWCNTs) for the production of highly soluble/dispersible materials has been accomplished by a class of highly reactive and thermally stable nitrones. Besides the unprecedented solubility in aprotic polar solvents of the functionalized samples (up to 10 mg of f-MWCNTs per mL of DMF), we have demonstrated, for the first time, that the CNT functionalization by nitrones preferentially occurs at the defective CNT sidewalls without any appreciable degradation of their sp2 network. The role of the reticular imperfections on the graphitic lattice of the MWCNTs has been experimentally and theoretically addressed. A complete chemical (TGA-MS, FT-IR, SSA) and morphological (TEM, AFM) characterization of the functionalized materials has accounted for the high degree of CNT functionalization, whereas Raman scattering, in combination with complementary XRPD and active surface area (ASA) measurements, has provided unambiguous evidence of the key role played by the structural “disorder” of the MWCNTs in the nitrone cycloaddition. Density functional theory (DFT) calculations on the reactivity of selected topological defects at the CNT sidewalls have contributed to trace-out a “defect-based” sidewall reactivity trend. The excellent processability of the functionalized MWCNTs has been finally exploited for the preparation of highly homogeneous CNT/polymer nanocomposites with CNT loadings as high as 3 wt%.