大侧基链接剂制备嵌段磺化聚芳醚砜质子交换膜及其性能研究

A series of high molecular weight ordered and disordered block sulfonated polyaryle ether sulfone (SPAES) were synthesized using phenyl-containing p-bis(phenylene-tetrafluorobenzene) as a linking agent, with 4, 4'-difluorodiphenyl sulfone and 4, 4'-dihydroxydiphenyl sulfone and 4, 4'-biphenyl sulfone as hydrophobic and hydrophilic block precursors, respectively. The ¹H-NMR showed that the sulfonation site of the prepared block SPAES was consistent with the prediction, and the titration value of the ion exchange capacity (IEC) was more than 95% of the theoretical value, indicating that the sulfonation position and sulfonation degree were precisely controllable. The Young’s modulus, tensile stress and elongation at break of the SPAES proton exchange membrane in this work are as high as 1.92 GPa, 75 MPa and 58%. The TGA results show that the block SPAES in this work has two stages of weightlessness, namely sulfonated group detachment at about 320 ℃ and polymer skeleton decomposition above 500 ℃ . Similar to IEC, the water absorption rate of SPAES with benzene ring large side linker varies significantly less with temperature than that of linkless SPAES, and the rate of change in the size of the membrane surface direction is comparable, both of which are about 8%. The proton conductivity of ordered blocked SPAES with linking agents with similar IEC, such as MB9 (IEC = 1.68 mmol·g⁻¹), is more than 1.2 times that of linkless blocked SPAES B2 (IEC = 1.70 mmol·g⁻¹). This is due to the benzene ring side chain structure of the linker so that the free volume in the membrane increases favors proton conduction. Similarly, the proton conductivity of ordered blocked SPAES PEM is higher than that of the same IEC type of disordered block.(Figure presented.)