Abstract: The present disclosure relates to a process for the preparation of a polymer composition including at least one polymer and at least one polyether compound (PE). The polymer is obtained by radical polymerization of a monomer composition (M) including at least one olefinically unsaturated acid monomer and optionally further monomers such as a chain transfer agent. The radical polymerization is carried out in at least one reactor operated in batch or semibatch mode and in the presence of the polyether compound (PE). The reactor comprises a volume-based heat removal power (A) of at least 3 kW/(m3·K) and has a volume of at least 10 L.