| 초록 |
Sulfonated poly(arylene ether sulfone) (SPAES) / polyimide (PI) block copolymers [SPAES/PI-X, X means ion exchange capacity (IEC)] were synthesized by coupling reaction between phenoxide terminated SPAES and phenoxide terminated PI oligomers. The coupling reaction was carried out using decafluorobiphenyl (DFBP) as a coupling agent under mild condition (＜ 105 oC). The low coupling temperatures prevented ether-ether exchange reactions which can cause a loss of order due to randomization of hydrophilic-hydrophobic sequences. The IEC of the copolymers was controlled by changing the feed ratio and molecular weight of the oligomers. The block copolymers produced high molecular weight and ductile membranes. The proton conductivity and water uptake increased with increasing IEC as expected. For example, when IEC of block copolymers increases from 1.40 to 2.02 meq/g, proton conductivity and water uptake also increased from 0.060 to 0.109 S/cm at 25 oC, and from 60 to 80% respectively. |
