en atom or a methyl radical, R3 is a linear or branched alkylene radical having 1 to 6 carbon atom(s) per radical and R4 is a linear or branched alkylene radical having 1 to 6 carbon atom(s) per radical, g is 0 or 1, n is 0 or an integer from 1 to 1500 and m is 0 or an integer from 1 to 100,with the proviso that the compound contains at least one radical A per molecule. 3.