Degradation of macromolecular chains in fullerene C60-polystyrene composites

Fullerene C-60-polystyrene composites prepared by mixing benzene solutions of polystyrene and of C-60 with subsequent lyophilization have been studied by hydrodynamic and optical methods. The distributions of effective hydrodynamic radii of polystyrene samples within a wide range of molecular weights have been compared to those of composites with fullerene by size exclusion chromatography in tetrahydrofurane. Simultaneously, under real conditions in a porous system of chromatographic columns with the medium (tetrahydrofurane), in which fullerene is virtually insoluble, the possibility of fullerene transport by polymer molecules because of the formation of the C-60-polystyrene molecular complex was investigated. Comparative analysis of spectra of composites, mixtures of polystyrene and fullerene as well as spectra of fullerene-containing star-shaped polystyrenes, in which the fullerene core is covalently bound to polystyrene arms, was carried out by UV spectroscopy. The experimental data suggests that during the preparing of composites and their subsequent dissolution the degradation of polystyrene chains occurs with the formation of a covalent bond between chain fragments and fullerene. A qualitative mechanism of polystyrene macromolecules degradation has been proposed.