Influence of montmorillonite and attapulgite clays on the production of polyamide 6 membranes via hot‐press fusion method

Abstract The membrane separation process represents an advance in this area, and the use of nanocomposites enables their improvement. Polyamide 6 (PA6) membranes were produced with attapulgite (ATP) and montmorillonite (MMT) clays by melting through the hot pressing of thin films. Subsequently, the membranes were characterized by thermogravimetry (TGA), showing a significant mass loss at 330°C. Differential scanning calorimetry (DSC) revealed that the clay increased thermal stability. X‐ray diffraction (XRD) was performed, confirming the presence of characteristic peaks of polyamide 6, and with the introduction of clay, there were changes in the shapes. Contact angle measurements showed that the clays increased the hydrophilicity of the membranes. Atomic force microscopy (AFM) revealed that the presence of clays modified the surface roughness. The tensile test showed that the clays decreased the strength of the nanocomposites. Oxygen permeation confirmed a decrease in the permeability of compositions containing clay compared with pure PA6 membranes. Studies aimed at understanding the interaction of gases with the membrane material represent a small part of research on the selective barrier. This work aimed to obtain flat membranes from polyamide 6/clay nanocomposites to separate gaseous mixtures using the thin film hot‐press fusion method. Highlights PA6 membranes were produced with ATP and MMT clays via hot pressing of thin films. Introduction of clay enhances thermal stability in PA6 membranes and reduce gas permeability. ATP clay increases membrane stiffness; MMT decreases strength. Membranes with PA6 and clays exhibit good water vapor selectivity.