A2??????O???(CH2CH2O)x???(CH2)n3???A2 [0093] where (x) represents the degree of polymerization (i.e. from about 10 to about 2,300) or number of repeating units in the polymer chain and is dependent on the molecular weight of the polymer, (n3) is zero or a positive integer, (A2) is a capping group as defined herein, i.e. an, amino, carboxy, halo, C1-6 alkyl or other activating group and (A???2) is