Influence of chemical structure of isophthaloyl dichloride and aliphatic, cycloaliphatic, and aromatic diamine compound polyamides on their chlorine resistance

Aromatic-cycloaliphatic polyamide thin-film composite membrane with improved chlorine resistance prepared from m-phenylenediamine-4-methyl and cyclohexane-1,3,5-tricarbonyl chloride

“…Chlorine uptake of the membrane material has been adopted to study the correlation of the material chemical structure and chlorine resistance, and higher chlorine resistance is expected for the composite membrane prepared with the material with lower value of chlorine uptake rate [20]. The chlorine uptake rates of polyamides prepared from different diamines and polyacyl chlorides were measured and the results are listed in Table 1.…”

“…Kawaguchi and Tamura [19] observed that reversible and irreversible chlorination occurred in polyamides upon chlorine exposure and these modes were dependent on the amine component of polyamide. Konagaya and Watanabe [20] prepared various polyamides from isophthaloyl dichloride and aliphatic, cycloaliphatic and aromatic diamines. The influence of the chemical structures of the polyamides on chlorine resistance was studied by measuring their chlorine uptake rates.…”

Nanofiltration membrane achieving dual resistance to fouling and chlorine for “green” separation of antibiotics

“…The costly pretreatments of de-chlorination and re-chlorination have triggered a meaningful request for chlorine tolerant membranes. Among various attempts to develop chlorine resistant membranes, the rational design of chemical structures of aromatic PA based TFC membranes to constrain aromatic PA chlorination has been proven as the potentially promising strategy [18][19][20][21][22][23][24][25][26][27]. Based on chlorine attacking mechanism, the chemical structure design can be considered from the following three rules: (1) substituting other moieties [e.g., methyl (-CH 3 ) or phenyl (-C 6 H 5 )] for chlorine sensitive amidic hydrogen on the amide linkages; (2) replacing the aromatic ring bonded to the amide nitrogen with aliphatic chain or cyclics; (3) preventing Orton rearrangement by adding protective groups at the possible chlorination sites on the aromatic rings.…”

“…Accordingly, polyamides derived from aliphatic diamines are expected to be free from aromatic ring chlorination. As reported, the chlorine resistance of polyamide membranes could be improved by utilizing several aliphatic diamine as aqueous monomers to react with poly acyl chloride, including ethylene diamine, isopropyl diamine, and p-xylylenediamine (bis-1,4-aminomethylbenzene) [18,21,22,25,26].…”

Thin Film Nanocomposite Membranes for Water Desalination

“…Therefore, this class of membranes is widely used in commercial single-pass seawater desalination plants around the world, and they offer a combination of high flux and high selectivity, which is unmatched by the CA membranes [14,15]. However, the PA membranes exhibit some drawbacks in desalination, such as chlorine and fouling susceptibility, which may worsen the membrane performance by shortening membrane life, and reducing flux or salt rejection [2,[16][17][18][19][20][21][22]. A great deal of effort has been made to modify the properties of PA TFC membranes by chemical or physical modification, but the improvement is still unsatisfactory [6].…”