Organoclays with different levels of reduction in the original cation exchange capacity (CEC) were prepared to characterize the morphology and Young's modulus of their melt-processed nanocomposites made from nylon 6 (PA-6) and polypropylene/polypropylene grafted with maleic anhydride (PP/PP-g-MA). Wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), and Young's modulus data are reported. Three different levels of CEC reduction were obtained; WAXS analysis and percentage loss on ignition (LOI) calculations for these organoclays showed a reduction in both the intergallery spacing and in the amount of organic modifier contained in the clay with CEC reduction. The morphology and modulus results show that these reduced-CEC organoclays led to lower exfoliation and modulus enhancement for both PA-6 and PP/PP-g-MA nanocomposites. The results may be influenced by differences in layer charge and charge distribution that could have been produced during the charge reduction process. (C) 2007 Wiley Periodicals, Inc.