The investigation presented here, including detection of nitrogen, the viscometric investigation, melting point determinations, the ultraviolet and infrared spectra, allow of the qualitative statement that macroradicals are formed in the mechanochemical breakdown of polystyrene by vibromilling. The slight differences between N2 and NO milling may be ascribed in part to a more rapid deactivation of the radicals. On the foundation of the existing knowledge of mechanochemistry there result interesting prospects for science and technology, e.g., the use of macro-radicals as polymerization initiators and as active types of block copolymers and graft polymers by reactions both with monomers and with macroradicals of other polymer materials.