Polyamide interfacial composite membranes prepared from m-phenylene diamine, trimesoyl chloride and a new disulfonated diamine

The influence of synthesis conditions (e.g., monomer concentration and membrane preparation protocol) on transport properties of polyamide thin-film composite (TFC) membranes prepared using m-phenylenediamine (MPD) and trimesoyl chloride (TMC) via interfacial polymerization is reported. For example, at 25 °C, NaCl rejection and permeate flux combinations of 99.6 ± 0.1% and 42 ± 3 L/(m2 h), respectively, were achieved in crossflow filtration using a 2000 ppm aqueous solution of NaCl and a transmembrane pressure difference of 225 psi (15.5 bar). Additionally, a sulfone diamine, disulfonated bis[4-(3-aminophenoxy)phenyl]sulfone (S-BAPS), was used in place of MPD to prepare TFC membranes. The resulting membranes had low NaCl rejection but somewhat higher permeate flux than MPD/TMC membranes. These membranes had reduced chlorine tolerance compared to those prepared using MPD as the diamine.

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► Polyamide TFCs were prepared from m-phenylenediamine and trimesoyl chloride.
► TFC membranes have 0.4 ± 0.1% NaCl passage and permeate flux of 42 ± 3 L/(m2 h).
► Post-polymerization thermal treatment did not improve rejection or permeate flux.
► TFC membranes were synthesized from S-BAPS, a disulfonated sulfone diamine and TMC.
► S-BAPS based membranes have higher permeate flux and lower rejection than MPD based ones.