The alkaline anion-exchange membranes were developed from poly (vinyl alcohol)/quaterized hydroxyethylcellulose ethoxylate(PVA/QHECE) by incorporating polyethylene glycol(PEG) as a plasticizer using chemical and physical cross-linking method. The PVA/QHECE/PEG membranes were characterized in detail at structural and hydroxyl ion (OH-) conducting property by AC-impedance spectroscopy, FTIR spec-troscopy, scanning electron microscopy (SEM), thermal gravity analysis (TG) , gas chromatogram (GC) and tensile strength technique. The results show that the membrane flexibility and mechanical property are highly improved by incorporating PEG, especially for the membranes with high content of QHECE. The thermal stability of the membranes with PEG (300 ℃) is 40 ℃ higher than that of without PEG (260 ℃). No decreaes in OH- condutivity was observed for the membranes after conditioning in 80 ℃, 6 mol/L KOH for 264 h. On the contrary, the OH- conductivity increased from 1. 06×10-3 S/cm (before conditioning) to 3. 88×10-3 S/cm(after conditioning) , while no obvious change in water uptake was observed. In addition, the methanol permeability of the PVA/PAADDA/PEG membranes are all lower than 10-7 cmVs, which is only 1/20—1/40 of Nafion? 117 under the same measuring conditions, indicating that the membranes are promising for potential use in alkaline direct methanol fuel cells.%通过对聚乙烯醇(PVA)/季铵化羟乙基乙氧基纤维素(QHECE)共混膜进行聚乙二醇(PEG)聚塑化改性,采用物理-化学交联联用法制备了PVA/QHECE/PEG碱性阴离子交换复合膜.通过交流(AC)阻抗、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、热重分析(TGA)、气相色谱(GC)和拉伸实验等手段考察了不同PEG添加量对膜的离子电导率、分子结构、微观形貌、热稳定性、力学强度、甲醇渗透率和耐碱稳定性等性能.结果表明,PEG的加入(除最小比例外)提高了膜的离子电导率和力学强度并使其柔韧性增大.同时,膜的热稳定性比未添加PEG时提高了40℃.将PVA/QHECE/PEG膜在80℃,6 mol/L KOH浓碱溶液中浸渍处理264 h,膜的电导率从1.06×10-3 S/cm提高到3.88×10-3 S/cm,而膜的外观和力学强度及含水率未发生明显变化,表明该膜具有很好的耐碱化学稳定性.此外,以3 mol/L甲醇溶液为测试目标,膜的甲醇渗透率＜10-7 cm2/s,仅为商业用Nafion@膜的1/20～ 1/40.
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