VERFAHREN UND POLYMER ZUR VERMEIDUNG VON BA/SR- KESSELSTEIN MIT NACHWEISBARER PHOSPHORFUNKTIONALITÄT

The present invention relates to a process for preparing a phosphorus-containing polymer, comprising the steps of (i) copolymerizing at least (a) monoethylenically unsaturated dicarboxylic anhydrides having from 4 to 6 carbon atoms with (b) olefins of the formula CH2 C(R1)R2 where R1 is H or CH3 and R2 is H, CH3, C2H5 or phenyl; (ii) reacting the polymer formed in step (i) with at least one primary or secondary phosphorus-containing amine or a phosphorus-containing alcohol and (iii) at least partly ring-opening the remaining anhydride groups. The invention further relates to phosphorus-containing polymers obtainable from this process, and to processes for preventing Ba/Sr scale with the aid of the polymer.