含偕胺肟基螯合纤维的制备及结构和性能的研究

通过羟胺与聚丙烯腈的反应制得含偕胺肟基螯合纤维,当腈基转化率为53.7％时,纤维对Au~(3+)的吸附量达626.7mg/g.对反应条件、纤维结构和性能相互关系的研究表明,聚丙烯腈的超分子结构致密性及序态越低越有利于反应;处理过程中,纤维蕴晶区在70℃时开始融化;纤维中偕胺肟基含量随羟胺浓度提高或反应时间延长而提高到一定值后变化趋于平缓,当反应温度高于70℃时,随反应温度升高而提高;纤维断裂强度随反应时间延长而下降;当反应温度高于70℃时明显下降。为获得偕胺肟基含量高、力学性能良好的纤维,聚丙烯腈纤维的偕胺肟化反应宜在略低于70℃的温度下以较短时间进行.

STUDIES ON THE PREPARATION, STRUCTURE AND PROP- ERTIES OF AMIDOXIME GROUP CONTAINING CHELATING FIBER

One kind of amidoxime group containing chelating fiber with high adsorption capacity to Au3+ ion (up to 626.7mg/g, when nitrile group conversion reaches 53.7%) was prepared by treating polyacrylonitrile fiber with hydroxylamine. The relationship between reaction conditions, fiber structure and properties was investigated. It is revealed that the decreases in tightness and regularity of PAN supermolecular structure are of advantage to raising nitrile group conversion. In the treatment process, the paracrystallite in the fiber begins to be fused at 70℃. The content of amidoxime group in the fiber increases at first then tends to steady value with the increase of hydroxylamine concentration for reaction time, and does not increase quickly until reaction temperature reaches 70℃. The fiber strength decreases with the increase of reaction time, while does not decrease until the temperature is up to 70℃. It is suggested that, in order to prepare a chelating fiber with high amidoxime group content and reasonable mechanical property, the reaction should be immediately carried out slightly below 70℃.