磷酸掺杂咪唑金翁盐聚苯醚基高温质子交换膜的制备和性能

Preparation and Characterization of Phosphoric Acid Doped Imidazolium Poly(phenylene ether) Membrane for High Temperature Proton Exchange Membrane

以强度高、加工性能好的聚苯醚为原料,制备耐高温Bronsted酸碱对型质子交换膜。采用自由基反应合成不同溴化度的溴化聚苯醚(BPPO),再与N-甲基咪唑(Im)反应生成咪唑金翁盐聚苯醚,最后通过掺杂磷酸(PA)制备了BPPO-Im/PA膜。利用核磁共振谱和红外光谱对膜的结构进行表征,计算得到溴化度分别为15.33%、28.66%、36.07%。随溴化度增加,接枝的Im量增加,吸附磷酸量增加,电导率先升高后降低,力学性能逐渐降低。溴化度为28.66%的B2-Im/PA膜综合性最好,该膜在200℃内使用时热稳定性良好,拉伸强度为5.2 MPa,160℃时电导率达到了0.054 S/cm,提高了将近一半。

Poly（phenylene ether）（PPO） was chosen as raw material because of its high strength and good processing properties,to prepare the high temperature Bronsted acid-base polymer membrane.PPO was first bromomethylated by free radical reaction,then reacted with different contents of methylimidazole（Im）,finally doping phosphoric acid（PA） to prepare BPPO-Im/PA membrane.The proton exchange membranes were characterized by13 C-NMR and FT-IR.The bromination degree is 15.33%,28.66% and 36.07%,respectively.The amount of Im increases with increase of the bromination degree and the PA uptake increases from 40% to 380%.The thermal stability of the BPPO-Im membranes is proved with increase of Im.The conductivity increases first and then decreases with increase of the PA uptake,and the mechanical properties decrease gradually.The B2-Im/PA membrane with the bromination degree of 28.66% exhibits the best comprehensive properties.The B2-Im/PA membrane has good thermal stability below 200 ℃detected by TG and good tensile strength of 5.2 MPa.A high conductivity of 0.054 S/cm is achieved at 160℃ for the membrane.