| abstract |
An oligomer or polymer of the formula (I): Q?1 - X1 - Y1¿ - Z - W wherein Q1- represents a hydrophobic moiety, -X1- and -Y1- are independently each absent or represent a suitable linking group, -Z- represents a hydrophilic chain; and -W represents hydrogen or a group of the formula -Y2-X2-Q2, each of -X?2, -Y2 and -Q2¿ being independently selected from the values for X?1, Y1 and Q1¿ as hereinbefore defined. |