Afterward, CuCl (34.7 mg, 4 eq, 0.35 mmol) was added under inert conditions to the still frozen reaction mixture followed by four cycles changing between vacuum and argon before the polymerization mixture was allowed to refreeze and set to 60 °C. The polymerization was carried out at 60 °C for 24 h. The reaction was then terminated by cooling in liquid nitrogen followed by the addition of methanol. After removal of the residual copper using a neutral AlOx column, the solvent was removed by freeze-drying at the Schlenkline in a few hours. The residue was dissolved in DCM and precipitated three times into cooled nhexane. The desired block copolymer was isolated by the removal of the leftover solvent under reduced pressure as a white powder.