STUDIES OF THE PREPARATION, STRUCTURE, AND PROPERTIES OF AN ACRYLIC CHELATING FIBER CONTAINING AMIDOXIME GROUPS

Polyacrylonitrile fiber was treated with hydroxylamine to form a chelating fiber containing the amidoxime group with high adsorption capacity to the Au3+ ion (up to 626 mg/g, when the nitrile group conversion reaches 53.7%), reasonable mechanical properties, and good thermal stability; the relationship among reaction conditions, fiber structures, and properties were investigated. The amidoxime group content rapidly increases to a steady value with increasing reaction time or HONH2 . HCl concentration, the fiber strength drops linearly with increasing reaction time, when the reaction takes place at the temperature where the morphology and order structure begins to be destroyed, and the amidoxime group content increases significantly, while fiber strength decreases remarkably. It is suggested that, to prepare a chelating fiber with high adsorption capacity and reasonable mechanical property, the reaction could be carried out at temperatures from 70 to 75-degrees-C, time of about 30 min, and concentration around 75 g/L.