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The article presents a study on the compatibility of clay nanocomposites with various clay concentrations. The research, which involved the structure, heat conductance, and microhardness of the nanocomposites ethylene-glycidyl methacrylate copolymer (EGMA)/clay and ethylene-acrylic ester-glycidyl methacrylate terpolymer (EAGMA)/clay and organoclays Cloisite 20A (C120A) and Cloisite 30B (C130B), revealed high compatibility between the nanocomposites and the organoclays.

Abstract: Polymer/organoclay nanocomposites based on an ethylene–acrylic acid copolymer (EAA), a high-density polyethylene (HDPE) grafted with maleic anhydride (HDMA) and HDPE/HDMA blends with 80/20 and 50/50wt/wt composition have been studied by thermogravimetry in nitrogen and air atmospheres. The following parameters have been determined from the thermogravimetric (TG) and differential thermogravimetric (DTG) curves of the samples: T 10, T 50, T max, the degree of conversion at 450°C and the residue. The study of the non-isothermal degradation kinetics of the neat polymers and their nanocomposites has allowed the determination of the activation energy of degradation, the rate of degradation and the reaction order. The analysis of all parameters has led to the conclusion that in the presence of clay, the thermal stability in nitrogen atmosphere decreases, while the thermal stability in air increases. Moreover, the effect of clay on the degradation behavior of the polymer matrix is more pronounced for the nanocomposites having fully exfoliated structure than that of the nanocomposites containing intercalated clay stacks. The results have been interpreted by the better dispersion of the clay layers in the exfoliated nanocomposites, leading to a better barrier effect for the oxygen flow in air and to an increase in the number of clay catalytic sites in nitrogen. [Copyright &y& Elsevier]

Abstract: The flammability, microhardness and transparency of nanocomposites based on poly(ethylene-co-acrylic acid) copolymers having different concentration of acrylic acid and different molar mass, their Zn ionomer and ethylene-glycidylmethacrylate copolymer as matrixes and on organically modified montmorillonite as a nanofiller have been investigated. The presence and the increase in the content of the clay lead to the increase in the limiting oxygen index and to significant reduction of the burning rate of all materials. The results from the Vickers microhardness measurements have shown that the addition of the clay to matrixes of polar functionalized polyethylenes leads to a significant increase in the microhardness of the materials, while the creep constant does not decrease significantly. The UV spectra show that the light transmittance of the materials does not change significantly in the presence of the clay, i.e., the nanocomposite films preserve the polymer transparency. The results have been interpreted by the intercalated structures of the nanocomposites investigated. [Copyright &y& Elsevier]