Synthesis of water‐soluble polymers containing sulfonic acid and amine moieties for the recovery of metal ions using ultrafiltration

Copolymers from 2‐acrylamido‐2‐methyl‐propane sulfonic acid (APSA) and N‐acryloyl‐N‐methyl piperazine (AP) were synthesized by radical polymerization with ammonium peroxydisulfate as the initiator. The copolymerization yield ranged between 93 and 95%. The copolymers were completely water soluble, and were characterized by FTIR and NMR spectroscopy. The copolymer composition was determined from elemental analysis through the S/C ratio. The binding capacity for metal ion was studied by the LPR technique at different pH and filtration factors. The retention depended strongly on the pH and on the copolymer composition. With increasing pH and increasing content of APSA units in the copolymer, the metal ion retention increased.