Synthesis of 4-Aminobenzoylpiperazine for Preparing the Thin Film Composite Nanofiltration Membrane by Interfacial Polymerization with TMC

A new synthesis method of aromatic diamine, 4-aminobenzoylpiperazine (4-ABP), was studied from 4-aminobenzoic acid and 1-formyl piperazine for the preparation of nanofiltration membrane. The structure of 4-ABP was identified by FT-IR spectra and ¹H NMR spectra. The resulting 4-ABP was used as aqueous monomer to fabricate a thin film on porous polyethersulfone (PES) ultra filtration membranes by interfacial polymerization (IP) with trimesoyl chloride (TMC) as organic monomer. The salt rejection order of these thin film composite (TFC) nanofiltration(NF) membranes is Na₂SO₄>MgSO₄>MgCl₂>NaCl. This sequence indicated that the membranes were negatively charged.