Preparation of a polyampholyte from polyacrylonitrile by the Hofmann reaction

A polyampholyte bearing NH 2 or COOH groups on alternate carbon atoms could be prepared by a one-step Hofmann reaction (Br 2 +NaOH) from polyacrylonitrile. The maximum NH 2 /COOH ratio is 1.1:1 with an isoelectric point of pH 3.3 to 3.4.