Morphology and Mechanical Properties of Rubber Toughened Amorphous Polyamide/MMT Nanocomposites

The effects of addition of an organoclay on the morphology and the mechanical properties of blends of an amorphous polyamide (a-PA) and an elastomer (with and without grafted maleic anhydride) prepared via melt processing arc reported. Transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) were employed to obtain a detailed quantitative analyses of the morphology of the elastomer particles for these nanocomposites containing 80 wt % a-PA and 20 wt % elastomer. Stress-strain diagrams and impact strength were measured as a function of organoclay content for blends containing maleated and unmaleated elastomer. It is clear that the addition of organoclay to blends can be an effective way for reducing elastomer particle size and enhancing stiffness when the elastomer is not maleated; however, for this system, toughness is not improved in spite of these morphological changes. Blends based oil the maleated elastomer give a more beneficial balance of toughness versus stiffness.