Synthesis of fluorinated polymer electrolyte membranes by radiation grafting and atom transfer radical polymerization techniques
Synthesis of fluorinated polymer electrolyte membranes by radiation grafting and atom transfer radical polymerization techniques
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DOI：
10.1016/j.polymer.2009.01.014
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发表时间：
2009-02
期刊：
影响因子：
4.6
通讯作者：
Maolin Zhai;Jinhua Chen;S. Hasegawa;Y. Maekawa
中科院分区：
文献类型：
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作者：
Maolin Zhai;Jinhua Chen;S. Hasegawa;Y. Maekawa
通过辐射接枝和原子转移自由基聚合(ATRP)合成了一种新型的聚合物电解质膜。首先，将2-溴-四氟乙基三氟乙烯基醚(BrTFF)辐射接枝到聚四氟乙烯(ETFE)膜上，制备了含溴的全氟化接枝聚合物。然后，以ETFE-g-PBrTFF接枝薄膜中的溴原子为引发剂，用CuBr-2，2‘-联吡啶(BPY)催化体系对ATRP进行处理。通过调节引发剂/溴化铜/联吡啶的摩尔比和反应温度，在ETFE-g-PBrTFF薄膜中制备了支化聚苯乙烯，其主链接枝率在100%以上。热分析表明，全氟聚(BrTFF)主链与ETFE相容，而烃类聚苯乙烯支链与ETFE-g-PBrTFF膜发生相分离。在ETFE-g-PBrTff-g-PS膜的接枝过程中，可以进一步引入磺酸基，使其在垂直于膜表面的方向上均匀分布。所得膜的苯乙烯接枝率为15%，表现出比商品Nafion117膜更高的质子传导性。与常规辐射接枝制备的ETFE-g-PSSA膜相比，它具有更好的化学稳定性。
A novel polymer electrolyte membrane was synthesized by radiation-induced grafting and consequent atom transfer radical polymerization (ATRP). First, bromine-containing perfluorinated grafts were prepared by radiation grafting of 2-bromotetrafluoroethyl trifluorovinyl ether (BrTFF) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film. Then, the bromine atoms in the ETFE-g-PBrTFF grafted films were acted as initiators, and the films were treated with Cu(I)-based catalytic system of a CuBr and 2,2′-bipyridyl (bpy) for the ATRP. By adjusting the molar ratio of initiator/CuBr/bpy and the reaction temperature, branched poly(styrene) with a grafting yield of above 100% on the poly(BrTFF) main chains was constructed in ETFE-g-PBrTFF films. Thermal analysis revealed that the perfluorinated poly(BrTFF) main chains were miscible to ETFE, whereas the hydrocarbon poly(styrene) branches were phase-separated from the ETFE-g-PBrTFF film. Sulfonic groups could be further introduced into the poly(styrene) grafts of ETFE-g-PBrTFF-g-PS films with homogeneous distribution in a perpendicular direction to the membrane surface. The resulting membrane with a styrene grafting yield of 15% exhibited higher proton conductivity than commercial Nafion 117 membrane. Likewise, it had better chemical stability than ETFE-g-PSSA membrane prepared by conventional radiation-induced grafting.