METHOD FOR OXIDIZING CATIONIC STARCH, AND AMPHOTERIC STARCH OBTAINED THEREBY AND HAVING CARBOXYL GROUP AND CATIONIC FUNCTIONAL GROUP

摘要

This process consists in reacting a cationic starch with hydrogen peroxide and hydrobromic acid or bromine, in aqueous solution, so as to oxidise selectively the hemiacetal groups of the cationic starch and optionally the hemiacetal groups of its products of acidic hydrolysis, to carboxylic groups. The carboxylic and cationic amphoteric starch thus obtained is characterised in that its carboxylic groups originate from the selective oxidation of the hemiacetal groups of the cationic starch and, optionally, of the hemiacetal groups of its products of acidic hydrolysis.