We employed four radical inhibitors to investigate their influences on the degradation of poly (4-vinylbenzyl chloride-styrene) based anion exchange membranes (AEMs) in alkaline solutions. It is found that the presence of the radical inhibitors could effectively restrain the nucleophilic attack of hydroxide ions to the AEMs according to the conductivity measurements, especially the one p-ethyl phenol (PEP), which could significantly protect the AEMs against the attack. More evidences including water uptake, swelling ratio as well as FT-IR analysis further proved this phenomenon by comparison those properties of the membranes before and after the stability test in 8 M KOH at 80 °C for 24 h. According to the ¹H NMR spectra, the quaternary ammonium groups of the AEMs were mainly degraded into tertiary amines in the hot alkaline solutions; while in the presence of PEP, this degradation was restrained and the quaternary ammonium groups maintained by reaction with PEP. Fenton test results further indicated that high oxidative stability of the AEMs benefited from the presence of a small amount of PEP, which could reduce the generation of the oxidants. Thus an inhibition reaction mechanism of the radical inhibitors preventing the AEMs from alkaline degradation is proposed.

我们使用了四种自由基抑制剂来研究它们对碱性溶液中基于聚（4-乙烯基苄基氯-苯乙烯）的阴离子交换膜（AEM）降解的影响。根据电导率测量，发现自由基抑制剂的存在可以有效地抑制氢氧根离子对AEM的亲核攻击，尤其是一种对乙基苯酚（PEP），它可以显着保护AEM免受攻击。更多的证据包括吸水率，溶胀率以及FT-IR分析，通过在8 M KOH中于80°C进行24 h的稳定性测试之前和之后的膜特性进行比较，进一步证明了这一现象。根据¹1 H NMR谱图表明，在热的碱性溶液中，AEMs的季铵基团主要降解为叔胺。而在PEP存在下，这种降解被抑制，并且通过与PEP反应保持了季铵基团。Fenton测试结果进一步表明，AEM的高氧化稳定性得益于少量PEP的存在，这可以减少氧化剂的产生。因此，提出了自由基抑制剂抑制AEMs碱降解的抑制反应机理。