Chem. Commun., 2025, Accepted Manuscript DOI: 10.1039/D5CC04700E, Communication Stefanie Hutsch, Sven Graetz, Jonas Lins, Torsten Gutmann, Lars Borchardt Herein, we report a solid-state polycyclotrimerization of 1,4-diethynylbenzene using mechanochemical activation in a ball mill, yielding a highly porous and hydrophobic hyperbranched polymer (HBP) with a specific surface area of...