Degradation of Macromolecular Chains in Fullerene C₆₀–Polystyrene Composites

Properties of casting solutions and ultrafiltration membranes based on fullerene-polyamide nanocomposites

“…For PVP with M w = 12 kDa the ["] value of its fullerene-containing complexes remains virtually constant (Table 2) [7]. These results are in good agreement with the model of polymerfullerene interaction suggested in [4]. It should be emphasized that for polydisperse compositions the ["] value is an integral parameter that allows rather comparing macromolecular sizes than determining them precisely.…”

“…As stated in the Introduction, fullerene molecule possesses the unique !-electron structure. Several authors used spectroscopy data to prove the existence of donor-acceptor interactions between polymer and fullerene in PS/C 60 [4] and PVP/C 60 [37] complexes. The authors of review [38] analyzed the data concerning changes of polymers properties in fullerene-doped polymer systems and suggested that the interaction between 'aromatic' C 60 and phenylene rings of polymers takes place.…”

“…Particularly, being !-acceptor, fullerene molecule can be incorporated into a wide variety of polymers via formation of donor-acceptor [1,2] or, in certain cases, covalent bonds [3,4]. Polymer-fullerene complexes can be prepared either by synthesis or by mixing components in solvent or in solid phase; they exhibit properties different from those of the pristine polymer.…”

“…The static methods, which affect the solution structure very slightly, clearly indicate the existence of intermolecular associates [7,10,11]. Dynamic methods such as liquid chromatography, viscometry, sedimentation, and birefringence in flow characterize only individual macromolecules since intermolecular associates existing in solution are destructed by velocity gradients during the experiments [4,7,10,12,14,15]. The change in polymer properties after modification by fullerene was demonstrated very clearly in the cases of poly(vinylpyrrolidone) (PVP)/fullerene and polystyrene (PS)/fullerene complexes.…”

“…The study of polystyrene/C 60 complexes by liquid chromatography showed that destruction of the polymer chain followed by the formation of PS-C 60 covalent bonds occurred during the preparation of the samples (mixing of C 60 and PS solutions with subsequent solvent evaporation and re-dissolving of the complexes). The degree of destruction increases with increasing polymer molecular weight (M w ) and deterioration of the solvent quality for fullerene C 60 [4]. Intrinsic viscosities of solutions of many polymer-fullerene complexes including polymers of different structure and M w were determined in various solvents [7,13,14].…”