以聚苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)为基质、炔丙基三甲胺盐(PTMA)为碱性功能基团,通过点击化学(click chemistry)法合成聚合物SBS-TMA,采用浇铸成膜法制得扩散渗析(DD)性能优异的均质型阴离子交换膜.借助核磁共振仪(1H NMR)、扫描电镜(SEM)对聚合物的结构、形貌表征;借助热重分析仪(TG)、精密天平对膜的热、酸性稳定性能表征.研究了功能基团含量和温度双重因素对其DD性能的影响,结果表明:在室温下,当功能基团的含量为0.20(即SBS-TMA-0.20)时,膜的扩散系数(UH+)为2.86×10-2m/h,分离系数(S)为28.1,该膜的 DD 性能是商业膜 DF-120(UH+=9×10–3m/h,S=18)的2~3倍;当系统温度由25℃升至70℃时,膜SBS-TMA-0.20的UH+值由2.86×10–2m/h增加至4.48×10–2m/h,它的S值由28.1增加至30.1,随后由30.1快速下降至16.2.%Homogeneous anion-exchange membrane featured with excellent efficacy of diffusion dialysis (DD)is prepared through casting process for modeling membrane method. The matrix is the segmented copolymer formed from polystyrene-butadiene-styrene and propargyl trimethylamine is adopted as the alkaline functional group. The synthesis of polymer SBS-TMA is achieved by click chemistry process. The chemical structure and morphology of the polymer are characterized by 1H NMR spectroscopy (1H NMR)and scanning electron microscopy(SEM). With the help of thermal gravimetric(TG) analyzer and precision balance,thermal and acidic stability of the membrane are studied. We have explored the impacts of the content of functional groups and temperature on its DD property. The results show that,when the content of functional group is 0.20(SBS-TMA-0.20),the diffusion coefficient (U H+)for the membrane is 2.86×10–2m/h,and the separation coefficient(S)is 28.1. The DD property of this membrane is twice to three times as good as that of the commercial membrane DF-120. When the system temperature rises from 25℃ to 70℃,the UH+of SBS-TMA-0.20 increases from 2.86×10–2m/h to 4.48×10–2m/h accordingly,and its S increases from 28.1 to 30.1,but then sharply reduces to 16.2.
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