(326f) Montmorillonite-Modified Aromatic Polyamide Membrane Materials with Chlorine Resistance

Aromatic polyamides (PA) are used in reverse osmosis (RO) membranes, and the attack by chlorination is of great commercial concern. Addition of nanoparticles such as montmorillonite nanoclays hold some potential to mitigate this attack in an aqueous environment. A thermal gravimetric analysis (TGA) method was used to enable the difficult detection of whether the montmorillonite could successfully protect the polyamide from N-chlorination. TGA studies focused on temperature of onset of degradation, char yield, activation energy and pre-exponential factor. The char yield and activation energy values did identify both chemical changes from aqueous exposure of the PA to hypochlorite ion as well as protective capacity when sodium montmorillonite was blended into the matrix.