部分氟化嵌段型阴离子交换膜的制备

Preparation of partially fluorinated block-type anion exchange membranes

以接枝α,α′二溴对二甲苯的氟化芳香族链段作为大分子引发剂,在链的末端引发烯烃聚合,合成了三嵌段聚合物.然后在脂肪族链段接枝季铵型侧链进行功能化,制备出部分氟化的嵌段型阴离子交换膜.表征结果显示,由于嵌段间的亲疏水性差异,膜内形成明显的微相分离.其中,膜FPAE PVBC QA 20(IEC=1.51 mmol/g)在80℃下离子电导率达到87.8 mS/cm;浸泡于80℃、2 mol/L NaOH溶液中500 h后仍保留74.5%的离子电导率,具有良好的耐碱性;单电池功率密度达到131.7 mW/cm^2.

Tri-block polymers were synthesized by using fluorinated aromatic blocks grafted withα,α′-dibromo-p-xylene as macromolecular initiators to initiate the polymerization of olefins at the end of chains.Subsequently,a quaternized side chain was grafted on the aliphatic block for functionalization to prepare partially fluorinated block-type anion exchange membranes.The characterization shows that significant microphase separation structures are formed in the membranes,due to the difference in hydrophilicity and hydrophobicity between the blocks.Among them,the membrane FPAE PVBC QA 20(IEC=1.51 mmol/g)has an ionic conductivity of 87.8 mS/cm at 80℃.Moreover,it retains 74.5%of initial ionic conductivity after being immersed in a 2 mol/L NaOH solution at 80℃for 500 h and exhibits good alkali resistance.The power density of single cell reaches 131.7 mW/cm^2.