Polyamide 66/EPR-g-MA blends: mechanical modeling and kinetic analysis of thermal degradation

The present investigation deals with the mechanical, thermal, and morphological properties of binary nylon 66/maleic anhydride grafted ethylene propylene rubber (EPR-g-MA) blends at different dispersed phase (EPR-g-MA) concentrations. The effects of EPR-g-MA concentration and dispersed particle size on the mechanical properties of the blends were studied. Analysis of the tensile data in terms of various theoretical models revealed the variation of stress concentration effect with blend composition and the improvement of interfacial adhesion between dispersed rubber phase and nylon 66 matrix. The thermal degradation of the blends was analyzed by nonisothermal thermogravimetric analysis (TGA). It was found that the activation energy (E-a) and overall reaction order of thermal degradation decreased with increasing EPR-g-MA content. The scanning electron microscopic (SEM) analysis showed a significant decrease in dispersed particle size with increasing EPR-g-MA content, which was explained on the basis of the level of chemical interaction (in situ compatibilization) between nylon 66 and EPR-g-MA. The surface morphology of the nylon 66/EPR-g-MA blends was illustrated by the roughness of atomic force microscopy (AFM) images. Copyright (C) 2008 John Wiley & Sons, Ltd.