Mechanism of interfacial polycondensation and the direct synthesis of stable polyamide membranes

Abstract The mechanism of membrane formation by interfacial polycondensation was studied. For the time‐conversion curves the equation was derived ( x′ = reduced membrane thickness). The membrane morphology was investigated by x‐ray scattering and electron microscopy. It was found that the polymer chains are mainly oriented perpendicularly to the interface in the direction of membrane growth. The order of chain packing decreases with increasing thickness. Stable polyamide membranes consisting of two layers can be obtained by formation of a supporting layer of crosslinked copolyamide on a thin layer of Nylon‐6,10. The swelling properties of these membranes were studied.