The present invention relates to copolymers which are obtainable from the free radical copolymerization of at least (a) a monoethylenically unsaturated carboxylic acid having 3 to 6 carbon atoms or the anhydride thereof with (b) a reaction mixture comprising a component of the general structural formula where R1, R2, R3, R4, independently of one another, are H or C1- to C4-alkyl, n and m, independently of one another, are an integer from 1 to 100 and R5 is H or methyl, a process for the preparation of the polymer according to the invention and the use thereof as a scale inhibitor.