Intercalates formed with polypropylene/maleic anhydride-modified polypropylene intercalants

The present invention is directed to intercalated layered materials and, optionally, exfoliates thereof, prepared by intercalating a layered material, e.g., a phyllosilicate, such as a smectite clay, with polypropylene and maleic anhydride-modified polypropylene intercalants. The intercalated layered material, in the form of a concentrate, is combined with a polypropylene matrix polymer since the addition of polypropylene matrix polymer, after shearing the concentrate for exfoliation, avoids degradation of the later added polypropylene matrix polymer, added after shearing of the concentrate. The polypropylene and maleic anhydride-modified polypropylene polymer can be intercalated in the form of a polymer or an oligomer capable of polymerization to form the polymer, (e.g., an ethylene oligomer or polymer and/or a propylene oligomer or polymer and/or copolymers thereof) or, can be unexpectedly easily intercalated as the oligomer or polymer by direct compounding, e.g., by combining the polypropylene oligomers and/or polymers in a mixing or extruding device at or above the polypropylene polymer melt temperature, to produce the intercalated layered material and, subsequently, the nanocomposite by addition of matrix polypropylene polymer. A nanocomposite concentrate composition comprising about 10 weight percent to about 90 weight percent of a layered silicate material and about 10 weight percent to about 90 weight percent of a matrix polymer comprising about 90-99.5% by weight of a polyolefin and about 0.5% to about 10%, preferably about 1% to about 6% by weight, of a maleic anhydride-modified polyolefin, based on the total weight of polyolefins, wherein the layered silicate material is dispersed uniformly throughout the matrix polymer. Shearing of the concentrate and later (after shear) addition of an added matrix polymer avoids thermal degradation of the added matrix polymer and optimizes the dispersion of the nanomer throughout the matrix polymer; provides increased tensile strength; and reduces degradation of the polymer by melt formation of a concentrate thereby decreasing heat degradation of added matrix polymer.