磺酸基在侧链萘环上的磺化聚芳醚质子交换膜的制备与性能研究

Synthesis and Characterization of Poly( arylene ether) s Proton Exchange Membranes with Sulfonic Groups Attached on Pendent Naphthyl Rings

以β-萘甲醛和2,6-二甲基苯酚为原料,合成出一种新型双酚单体.以此双酚单体和二氟单体(4,4'-二氟二苯甲酮或4,4'-二氟二苯砜)为基础,通过亲核取代反应,制备出两种高分子量聚芳醚.用氯磺酸对聚合物进行磺化,得到了2种磺酸基在侧链萘环上的磺化聚芳醚.该磺化聚芳醚能溶于N,N-二甲基乙酰胺(DMAc)、N,N-二甲基甲酰胺(DMF)、二甲基亚砜(DMSO)等常见的有机溶剂,通过溶液浇注的方法制备出光滑、柔韧的膜.用红外光谱(FTIR),核磁共振谱(1H-NMR)表征了聚合物结构.用示差扫描量热仪(DSC),热重分析仪(TGA)研究了聚合物的耐热性能.结果表明,这些侧链磺化的质子交换膜具有高的电导率(4.2×10-2S/cm)、高的机械强度、低的溶胀率和较好的氧化稳定性.

Two novel poly（arylene ether）s with sulfonic acid groups attached on pendent napthyl rings were prepared from bis（3,5-dimethyl-4-hydroyphenyl）-β-naphthyl methane via nucleophilic aromatic substitution polycondensation with bis（4-fluorophenyl） ketone and bis（4-fluorophenyl） sulfone,followed by sulfonation with chlorosulfonic acid.The sructrues of polymers were confirmed by 1H-NMR and FTIR.The results showed that the sulfonation position took place only on the pendent naphthalene ring due to the specially designed molecular structure.The sulfonated poly（arylene ether）s can be dissolved in DMAC,DMF,DMSO and other common organic solvents,so they can be cast into smooth and flexible films.The proton conductivity of film 3b can reach 0.042 S/cm at 80 ℃,equal to the conductivity of Nafion 117 in the same condition.In addition,the swelling rate of these polymers is less than 11.5% and the tensile strength is more than 39 MPa.In a word,the films of side-chain-type sulfonated polymers showed high proton conductivity,high mechanical strength,low swelling rate and good oxidation stability,which can meet the requirement of proton exchange membranes.And the two novel poly（arylene ether）s are expected to be used as proton exchange membranes for fuel cells.