Amines play a significant role in materials science, especially as crosslinkers. In the field of polymers and, in particular, in the contest of covalent adaptable networks (CANs), multifunctional amino-terminated molecules have become crucial in the development of recyclable materials based on various exchange chemistries. This drives a significant interest in the development of novel polyamine crosslinkers. Moreover, the precise control over the macromolecular architecture, obtainable by Atom Transfer Radical Polymerization (ATRP), can be used to fine-tune the mechanical properties of the resulting materials. Herein, we describe the use of star-shaped amino-terminated polystyrenes, obtained by Activators Regenerated by Electron Transfer (ARGET) ATRP, as rigid crosslinkers in both conventional thermosets and CANs.