以1,4-双(二苯基膦)丁烷为交联剂,以具有四甲基联苯结构的聚芳醚酮为基体材料,分别制备了刚性三苯基膦和柔性三丁基膦修饰的阴离子交联膜材料.交联剂在交联结构形成的过程中转变成季膦盐,在提高膜材料机械稳定性的同时保持离子交换功能基团的含量.研究了2种阴离子交换膜的尺寸稳定性、电导率、机械性能及耐碱稳定性等.研究结果表明,当交联度为20%时,三苯基膦与三丁基膦修饰的阴离子交换膜的拉伸强度分别由未交联时的27和18 MPa提高到45和30 MPa;交联的膜材料在60℃的3 mol/L KOH溶液中浸泡120 h后,三苯基膦修饰的阴离子交换膜的电导率保留率为81%,三丁基膦修饰的阴离子交换膜的电导率保留率为69%,膜的耐碱稳定性均较未交联时有明显提高.交联度相同时,三苯基膦修饰的阴离子交换膜表现出更高的拉伸强度和更好的耐碱稳定性.
Two phosphines,rigid triphenylphosphine( TPP) and flexible tributylphosphine( TBP),were chosen to functionalize tetramethylbiphenyl-contained poly( aryl ether ketone)( PAEK),respectively,to prepare anion exchange membranes( AEMs). 1,4-bis( diphenylphosphino) butane was used as the crosslinker to crosslink PAEK,and the crosslinker was quaternized simultaneously. Thus the amount of functional groups of the crosslinked membranes was as the same as those of the uncrosslinked phosphonium-based PAEK membranes. Moreover, the mechanical properties of the crosslinked membranes were more effectively enhanced. The dimensional stability,conductivity,mechanical property and alkali resistance stability of the AEMs were investigated. As the crosslinking degree increased from 0 to 20%,the tensile stress of TPP and TBP modified AEMs increased from 27 MPa to 45 MPa,and from 18 MPa to 30 MPa,respectively. After exposed to 3 mol/L KOH at 60 ℃ for 120 h,the TPP and TBP modified AEMs maintained the conductivity of81% and 69%,respectively. The results indicate that the alkaline stability of the crosslinked phosphoniumbased PAEK membranes is more effectively improved than that of the uncrosslinked ones. At the same crosslinking degree,the TPP modified AEMs exhibit higher tensile stress and better alkali resistance stability than that the TBP modified ones.