Patent ID: 7053150

Claim:
A water soluble polymer comprising: (i) a first water soluble polymer segment having at least 4 and at most about 2000 monomeric units (POLY A ); (ii) a second water soluble segment comprising 1 to about 120 monomeric units (POLY B ), which has a lower molecular weight than that of POLY A and is covalently attached to POLY A through a linkage X; and (iii) a functional group, Y, attached to POLY A or POLY B ; wherein each of POLY A and POLY B independently comprises one monomer or up to three different monomers selected from the group consisting of alkylene glycol, olefinic alcohol, vinylpyrrolidone, hydroxyalkylmethacrylamide, hydroxyalkylmethacrylate, saccharide, α-hydroxy acid, phosphazene, oxazoline, and N-acryloylmorpholine.