Polymacromonomers consisting of oligostyrene side chains (700 less than or equal to M(n) less than or equal to 5000 g/mol) and of a high molar mass polymethacrylate main chain are shown to exhibit a bottlebrush structure in that the PMA main chain adopts an extremely stiff conformation (i.e., a Kuhn statistical segment length of up to iota(k) = 2000 Angstrom) which is surrounded by the expanded but still flexible polystyrene side chains.