Oxygen permeation properties of HDPE-layered silicate nanocomposites

The current manuscript describes the effects of two different processing conditions on the barrier properties of HDPE/MMT nanocomposites. It is well known that the exfoliation degree of the primary clay mineral determines the gas permeation properties of the final composite. The tortuosity effect caused by the dispersed nanolayers improve the gas barrier properties in some cases while in other cases the interfacial regions or the free volume variations may overcome the tortuosity impact reducing the barrier effectiveness. In the present work, twenty MMT-HDPE nanocomposites were obtained using two types of commercial clay, two compatibilizers, and two different processing methods. The exfoliation and agglomeration of the nanocomposites were investigated by WAXD and TEM. Their gas permeability was measured as a function of the filler loading and was correlated to their impermeable inorganic volume fraction. The oxygen permeability of the nanocomposites decreased as much as 40 % when compared to the pure HDPE.