A polymer nanocomposite comprises a polymer; and a nanoparticle derivatized to include functional groups including carboxy, epoxy, ether, ketone, amine, hydroxy, alkoxy, alkyl, aryl, aralkyl, alkaryl, lactone, functionalized polymeric or oligomeric groups, or a combination comprising at least one of the forgoing functional groups. The variability in tensile strength and percent elongation for the polymer nanocomposite is less than the variability of these properties obtained where an underivatized nanoparticle is included in place of the derivatized nanoparticle.