Synthesis of the new ion exchangers based on polyacrylonitrile fiber Nitron C

Abstract

New ion exchangers based on polyacrylonitrile fiber were obtained by catalytic amination of nitrile groups with tetraethylenepentaamine and pentaethylenehexaamine. Chelating ion exchangers with aminodiacetic functional groups were obtained on the base of these materials. The acid-base parameters of the functional groups of obtained ion exchangers were determined by potentiometric titration: initial polyampholytes have a high anion exchange capacity (E b = 4.5–5.5 m-eq/g) distributed between three types of groups with pK a equal to 3.3, 6.2 and 9.2, and a cation exchange capacity with E a ≈ 1 m-eq/g and pK a ≈ 10.7; chelating ion exchangers on their base contain three types of acid groups with pK a approximately equal to 3.5, 6.0, 10.5 and two types of anion-exchange groups with pK a equal to 2.0 and 6.0. Initial polyampholytes have a high efficiency in the processes of air purification from acidic impurities (experimental data for sulfur dioxide), chelating ion exchangers – in the processes of water purification from heavy metal ions.