Acid-Base Properties of Ion Exchangers. IV. Synthesis and Potentiometric Analysis of Polyampholytes on the Base of Polyacrylonitrile Fibers

Abstract

A model for potentiometric analysis of spatial polyampholytes has been developed. It allows calculation of acidity parameters for all kinds of functional groups in the sorbent and reconstruction of the full titration curve of polyampholyte from the state of complete protonation (strong acid medium) to the state of complete deprotonation. Synthesis of new amino-carboxylic polyampholytes by reacting a PAN fiber with hydrazine and sodium sulphide is described. Computer analysis of potentiometric titration curves shows that the new polyampholytes contain four types of functional groups.

Keywords:

• Polyampholytes
• ion exchangers
• potentiometric titration
• ion exchange fibers
• polyacrylonitrile modification