N-methylimidazolium functionalized strongly basic anion exchanger: Synthesis, chemical and thermal stability

The synthesis and characterization of gel and porous strong base anion exchangers with N-methylimidazolium functional groups and the evaluation of their chemical stability in aggressive media and thermal behavior are reported. Strong base exchange capacity values, FT-IR spectroscopy as well as ESEM images proved the content of ionic groups and the morphology structure of the anion exchange resins. Both synthesized resins presented a very good chemical stability in hydrogen peroxide compared to the commercial strong base anion exchange resin, Amberlite IRA-400. It was also shown that the porous strong base anion exchange resin exhibited a better stability in aggressive media of high concentration than gel-type resin. The thermal stability of the samples was evaluated by dynamic thermogravimetric analysis in nitrogen gas. Comparing the TG and DTG curves it can be found that the degradation curves of the samples are close to each other in shape under the heating rate conditions. The differences for the samples between in the different heating rate are the typical temperatures and the residue rate of the decomposition. (C) 2009 Elsevier Ltd. All rights reserved.