In order to improve the ion conductivity and alkaline stability of the anion exchange membranes derived from quaternary ammonium poly(ether sulfone)s

a series of new self-crosslinked membranes (CQPES) were successfully prepared from three kinds of aliphatic di-tertiary amines

namely

N

N

N'

N'-tetramethylethylenediamine (TMEDA)

N

N

N'

N'-tetramethyl-1

3-propanediamine (TMPDA) and N

N

N'

N'-tetramethyl-1

6-hexanediamine (TMHDA)

by solution casting.For the CQPES membranes

their properties such as solvent resistance

dimensional stability

mechanical stability

hydrolytic stability as well as alkaline stability were enhanced significantly

while the high ion conductivity was maintained.For example

the membrane of CQPES-H-0.5 (1.45 mmol/g

TMHDA as the cross-linker) showed 43% of water uptake

lower than 10% of size change in in-plane direction at 30℃

and 17 mS/cm and 64 mS/cm of ionic conductivity in water at 30℃ and 90℃

respectively.During the evaluation of stability

21% loss in ionic conductivity after treatment in 4 mol/L NaOH solution for 168 h and 3.8% loss in weight after treatment in 100℃ water for 24 h were found for CQPES-H-0.5 membrane

while 12% and 40% losses were for the uncrosslinked membrane (QPES)

respectively.The excellent performance of CQPES-H-0.5 suggests its potential application in the fuel cell system.