. . . "r at 25??C of 1% or greater, a molecular weight of from 200 to 50,000, and selected to be covalently bonded to B;B is a hydrophobic moiety having a molecular weight of from 300 to 60,000, a solubility of less than 1% in water at 25??C, capable of being covalently bonded to A;C and D are terminating groups which can be A or B, can be the same or different groups,w is 0 or 1;x is an integer of 1 or" .