Effect of the amino-carboxylate as volatile compatibilizer in EVA/clay nanocomposites

Abstract

The scope of this study involves the evaluation of the effect of amino-carboxylate (AC) compound on the structure, thermomechanical and rheological properties of EVA (19 wt. % vinyl acetate)-clay nanocomposites. Two commercial organoclays were pre-swollen in AC compound at 1, 2.5 and 5 wt. %, in a solvent free procedure. Later, a torque rheometer dispersed the organoclays/AC mixtures in EVA matrix. The X-ray diffraction (XRD) and Fourier transfer infrared (FTIR) spectroscopy carried out the volatilization and interaction of AC with the organoclays as well as the structure of nanocomposites. The shear flow in a parallel plate rheometer followed the change in the viscosity of the nanocomposites. These changes depended on the organoclay and the synergy between the organoclays and AC concentration. Thermal analysis was evaluated using a Thermogravimetric analysis (TGA) and Dynamic scanning calorimetry (DSC). The AC compound decreases the catalization effect of organoclay in the deacetylation reaction of EVA. Mechanical properties were also evaluated. The increase in the Young modulus and elongation (as measured via tensile testing), provided evidence of a good level of dispersion and surface interaction in the EVA/clay/AC nanocomposites. These results demonstrate the feasibility to use amine-carboxylate compounds as compatibilizer in polymer/clay nanocomposites to enhance their performance.