To address this challenge of minimizing structural network defects, a homogeneous reaction mixture prior to gelation is essential, especially for systems based on components of different polarity. Accordingly, in addition to a hetero-complementary end group reaction with high conversion, a sufficiently slow and adjustable viscosity increase is of particular importance, i.e., a cross-linking reaction with an adjustable moderate reaction rate and a suitable non-selective solvent for both star polymers is desired.