Amine modified polyhedral oligomeric silsesquioxane (POSS-NH(2)) was used to modify sodium montmorillonite (MMT) nanoclays for improved dispersion in epoxy resin. The dispersion of the clay particles was inspected using scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-Ray diffraction and the thermal properties compared using differential scanning calorimetry (DSC) and thermogravametric analysis. The introduction of the amine-POSS was found to have a positive effect on the dispersion of the MMT clays and prevented agglomeration. The absence of clay agglomerates lead to an increase in glass transition temperature (T(g)) from 44 degrees C in the samples with the untreated clay up to 54 degrees C in the samples with 10% additional POSS-NH(2). The addition of POSS-NH(2) initial increase of the weight loss (T(d) (5%)) but slowed down the rate of degradation due to the formation of an inert silica layer and eventually leading to an increased charyield. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 3212-3216, 2011