纤维素基磁性聚偕胺肟树脂的研究——溴在树脂上的氧化还原反应

Studies on Cellulose-Based Magnetic Polyamidoxime Adsorbents-Redox Resction with Bromine

用羟胺作模拟物与溴反应，测定了吸溴前后的酸式纤维素基磁性聚偕胺肟树脂的红外光谱，结合Ｆｒｅｕｎｄｌｉｃｈ及Ｌａｎｇｍｕｉｒ等温吸附方程的分析和吸溴前后树脂重量变化的测定，证明纤维素基磁性聚偕胺肟树脂吸溴后随即发生氧化还原反应，偕胺肟基被氧化为羧基，溴则被还原为溴离子，在溴浓度较高时，纤维素葡萄糖单元上的羟基被溴代或被氧化成羧酸，若葡萄糖苷键氧化断裂，将导致大分子降解。

Hydroxylamine was used as a model compound to react with bromine, and the IR spectra of the acidic cellulose-based magnetic polyamidoxime adsorbent(AMAO) before and after adsorption of bromine were determined. Combined with the analysis of Freundlich equation and Langmuir adsorption isotherm, and the weight of adsorbents changed after adsorption, it proves that the redox reaction between AMAO and bromine takes place during adsorption. As a result, the amidoxime groups were oxidized to be carboxylic groups and the bromine converts into bromide ions. In the higher bromine concentration, the hydroxy groups on glucose residue of cellulose core are subjected to bromination. Oxidation scission of the glucosidic bonds leads to the degradation of the macromolecules.