Synthesis of C₆₀-End-Bonded Polymers with Designed Molecular Weights and Narrow Molecular Weight Distributions via Atom Transfer Radical Polymerization

Abstract

Bromo-terminated polystyrene (PSt-Br) and poly(methyl methacrylate) (PMMA-Br) with designed molecular weights and narrow molecular weight distributions were prepared by atom transfer radical polymerization (ATRP). These bromo-terminated polymers were allowed to react with C60 under ATRP conditions to yield C60-end-bonded PSt (PSt-C60-Br) and PMMA (PMMA-C60-Br). The polymers were characterized by gel permeation chromatography (GPC), UV-vis, FT-IR, and fluorescence spectra. GPC profiles obtained by UV and RI dual detectors indicated that C60 had been covalently bonded to the polymers, and most of the C60-end-bonded polymers were monosubstituents. Furthermore, 2-aminoacetonitrile (AAN) was used as an IR label to react with PSt-C60-B; the products thus obtained show a characteristic absorption of CN group at 2369 cm -1 . This result reinforces the conclusion that C60 has been covalently bonded into the polymer. The fluorescence of PMMA-C60-Br and PSt-C60-Br can be quenched by triethylamine or fumaronitrile, indicating that C60 still keeps its strong electron-accepting and strong electron-donating property after it was modified by macromolecules. A possible mechanism of the formation of C60-end-bonded PSt was deduced tentatively.

Conventional and atom transfer radical copolymerization of phenoxycarbonylmethyl methacrylate-styrene and thermal behavior of their copolymers

“…In addition, as PCMMA unit increased in the resulting copolymers, PD (M w /M n ) was increased FT-IR spectra of PCMMA-St copolymer system was 1.64<M w /M n <1.87. This sugests that the contribution of chain breaking and transfer as well as termination reactions during copolymerization can be neglected until a higher polymerization conversion, which is similar to the results reported by Zhou et al [17]. The results are summarized in Table 1 and Table 2, respectively.…”

Self-Assembly of Stimuli-Responsive Water-Soluble [60]Fullerene End-Capped Ampholytic Block Copolymer

“…Although the above polymers were synthesized by cycloaddition reaction of azide-terminated polymers with fullerene, the atom transfer radical polymerization (ATRP) technique has recently been used to synthesize well-defined fullerene-containing polymers. For instance, Zhou and co-workers employed this technique to synthesize well-defined fullerene-containing polystyrene and poly(methyl methacrylate) [14]. The well-defined diand tetra-adducts of polystyrene-C 60 have been synthesized using ATRP by Audouin et al [15].…”

Stimuli‐Responsive Water‐Soluble Fullerene (C60) Polymeric Systems

“…radical polymerization, and then C 60 was subsequently incorporated to this block copolymer at the chloromethyl group on PCMS segment via ATRA (Scheme 5 ). Li and coworkers [ 86 ] used ATRP technique to synthesize well-defi ned PS and poly(methyl methacrylate) (PMMA) end-capped with C 60 (Scheme 6 ). First, well-defi ned-Br terminated PS and PMMA macroinitiators were synthesized by ATRP of styrene and MMA using 1 -phenylethyl bromide and methyl-2 -bromopropionate as initiators respectively, and CuBr/bipyridine (CuBr/bipy) as the catalyst system.…”

“…However, Mathis and co-workers demonstrated that di-and tetra-PS chains were attached to C 60 by direct addition of PS macroradicals prepared by ATRP onto C 60 in the presence of CuBr/bipy at 100 ° C regardless of the stoichiometry of PSBr/C 60 , [ 91 ] which contradicted the fi ndings of Li and coworkers. [ 86 ] They explained that a C 60 -Br bond was easier to break than the terminal C-Br bond of PS-Br, therefore even numbers of PS arms were attached to C 60 core. ATRP was also used to synthesize mono end-capped C 60 with rod-coil block copolymers of terfl uorene-b -PS segments in the presence of CuBr/bipy catalyst system in o -dichlorobenzene at 110 ° C. [ 92 ] The resulting C 60 end-capped polymer exhibited the emission of stable blue light.…”