Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7824006 | Polymer Degradation and Stability | 2018 | 31 Pages |
Abstract
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 8â¯M KOH at 80â¯Â°C for 24â¯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.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Niya Ye, Yixin Xu, Dengji Zhang, Jingshuai Yang, Ronghuan He,