In the present work, polymeric membranes based on poly (lactic acid) and bionanocomposites of PLA and cloisite clay 20A were produced, using the evaporation method with the solvent chloroform in the proportion 15:85 (clay mass: total mass, with addition of 3 and 5%). Still, to evaluate the influence of the addition of charge on the polymeric structure and on the barrier properties of the membranes and bionanocomposites, tests of X-ray diffraction (XRD), contact angle, scanning electron microscopy (SEM), water vapor permeation test and apparent porosity test. By means of the X-ray diffraction technique, bionanocomposites containing loads of 20A cloisite clay were obtained, with concentrations of 3% and 5%. The obtained results revealed a semicrystalline structure consistent with the findings described in the literature. In other words, the typical crystalline peaks of both polymer and clay were observed. From the results of the contact angle test, it can be verified that the addition of clay in the polymeric matrix caused alteration in the hydrophilicity of the bionanocomposites. Scanning electron microscopy analysis showed a dense structure without visible pore formation. Based on the results obtained from the water vapor transmission test, it is possible to state that the addition of clay fillers to the polymeric matrix resulted in an increase in the permeability of the membrane, indicating a good interaction between the clay and the polymer. The characterization by the apparent porosity test showed that the bionanocomposite with 5% filler ratified the best results in two time intervals (30 and 45 minutes), meaning an intercalated formation of the clay with the polymer. In this way, it was possible to obtain a bionanocomposite with satisfactory characteristics and results in permeation properties for application in gas separation and as a filter material.