repeating units in random order n is an integer from 2 to 70 preferably from 4 to 20 m is an integer from 2 to 250 preferably from 9 to 20 x is an integer from 1 to 100 preferably from 1 to 10 and in another embodiment of the invention block copolymers are provided having the following repeating units r is an integer from 2 to 135 preferably from 75 to 135 s is an integer from 15 to 65 preferably from 30 to 50 and z is an integer from 2 to 50 preferably from 5 to 20 the molecular weight of a block copolymer of the invention as measured by gel permeation chromatography against poly oxyethylene standards may range from 10 000 to 500 000 preferably from 50 000 to 250 000 the polymers can be prepared by a process wherein one or more dihydroxy terminated polymers selected from poly ethylene glycol poly higher alkylene glycol and block copolymers thereof are reacted in solution with a dihalomethane in the presence of a base examples of suitable solvents in which the reagents can be dissolved include dihalomethanes and other known organic solvents such as benzene chlorobenzene and toluene or mixtures thereof preferably an excess of the dihalomethane reagent is used as the solvent even though the dihalomethane is used in an amount which can far exceed the stoichiometric amount needed to couple with the polymeric reactants products of high molecular weight can still be achieved although any dihalomethane or mixture thereof may be used such as dichloromethane dibromomethane or diiodomethane the preferred dihalomethane is.