摘要 |
Copolymers of formula I are described <CHEM> in which A is the monomeric unit of a natural or synthetic polymer, m is the degree of polymerization; m and n are different one from the other, and m is a number between about 10 and about 10,000 and n is a number between about 100 and about 250; R is a quaternary ammonium radical; x<-> is an anion. A may be the monomeric unit of starch or the monomeric unit of hydroxyethylcellulose. |