A polypropylene nanocomposite composition having at least the following two elements. The first element is a maleated polypropylene polymer having a weight average molecular weight greater than 100,000. The second element is a cation exchanging layered silicate material dispersed in the maleated polypropylene so that more than one half of the layers of the cation exchanging layered silicate material are present as one, two, three, four or five layer units upon examination by electron microscopy. A thermoplastic olefin nanocomposite composition can be obtained by interdispersing a thermoplastic elastomer phase with the above-described polypropylene nanocomposite composition.