The Synthesis And Characterization Of Fullerenes C60, C70 Polymer Derivatives

Fullerene molecules were found to be highly reactive toward various organic reagents. Extension of these basic organic reactions into polymerization chemistry results in synthetic strategies for the design and preparation of fullerene-derived macromolecules. Covalent attachment of fullerenes to specific polymer may allow to combination of the outstanding characteristics of fullerenes with those of the polymeric matrix, and thus may lead to novel materials with unprecedented properties and applications, such as high temperature superconductive, biomedical, electroactive and photoactive materials with non-linear optical properties, conducting devices. Preparation of fullerene modified polymers may contribute to open a new era for their technological applications. The key to the development of polymer-bound fullerenes materials is to synthesize soluble and processable fullerenated polymers with specific structures in high yield under mild conditions. This thesis was focused on the synthesis and characterization of fullerene-modified polyvinyl derivatives by anionic and free radical reaction on fullerene. The contents of this thesis include six chapters. The particular emphasis on the synthesis and characterization of fullerene C70 modified polymer derivatives was made for their comparison to those of C60.In chapter 1, the advanced development in the research of fullerene modified polymer derivatives was reviewed. Especially, we summarized systematically the characteristic structure and properties of C70, and the recent achievements in the polymerization and functional materialization of C70.In chapter 2, the C70 chemically modified polystyrene and poly(p-methylstyrene) were synthesized in sodium naphthalene-initiated anionic polymerization reactions. The structure of these copolymer were confirmed by a variety of characterization techniques such as UV-Visible, FT-IR, GPC, TGA, 13C NMR, 1H NMR, XRD, DSC and SEM. The C70 fullerene polystyrene, poly(p-methylstyrene) copolymers prepared by one-pot method exhibit a lower intrinsic viscosity and a higher absolute molecularweight compared with linear polystyrene, suggesting that the copolymer possess higher branching structure. Meanwhile, in a two-step method preparation through direct reaction of "living" dianionic polystyrene, the linear dumbbell like C70-fullerene polystyrene derivatives were prepared. The GPC analysis showed the C70-styrene copolymers and the parent polystyrene have nearly the same molecular weights. From the GPC data and the C70 contents of the copolymers determined by TGA, it was confirmed that the C70-polystyrene derivatives were linear dumbbell-like macromolecules, in which two C70 molecular end-capped together by a polystyrene chain.In chapter 3, direct fullerenation of polystyrene (PS) and polyacrylonitrile (PAN) was achieved by simple irradiating a benzene solution of PS, or benzene/DMF solution of PAN with C70, and C60 at room temperature using a conventional UV lamp or by warming up a fullerene ( C60 or C70 )solution to a elevated temperature ( 70℃) in the presence of azo-isobutyronitrile (AIBN) Molecular weights of the C70 modified polystyrene were much higher than that of the parent polymer, suggesting that the fullerenation was realized via multiaddition of radical PS chain to C70 core. It was found that the reaction was completed in 12 h when it's irradiated by a UV lamp. The AIBN-initiated fullerenation reaction of polystyrene didn't complete until the mole ratio of AIBN of C70 exceeded 6~8. The products of AIBN initiated reaction of PAN with C60 or C70 at 70℃ were less soluble, probably due to the by-reaction of uncontrolled multiaddition of PAN chain radicals to fullerene.In chapter 4, we report synthesis and ESR Spectrum study of C60-polystyrene by free radical reaction of polystyrene and C60 under UV photoinitiator. It was found , that the extent of fullerenation can be controlled by varying the C60 feed mass ratio. The products were characterized by UV-Vis, FTIR, GPC, TGA and DSC techniques. From the GPC data and...