ATNRC/SET-NRC synthesis of graphene/polyisobutylene nanocomposites

Abstract

Two polyisobutylene‐grafted graphene nanocomposites were prepared by CuBr‐catalyzed atom transfer nitroxide radical coupling (ATNRC) and Cu‐catalyzed single electron transfer‐nitroxide radical coupling (SET‐NRC) chemistry under mild conditions, respectively, through the grafting‐onto strategy. Graphene oxide was first reduced to graphene by diazonium addition reaction followed by treating graphene with ethyl 2‐bromoisobutyrate for introducing Br‐containing groups onto the surface to give G‐Br. The presynthesized well‐defined functional polyisobutylene (PIB) possessing 2,2,6,6‐tetramethylpiperidine‐1‐oxyl terminal group obtained via cationic polymerization of isobutylene was then coupled with G‐Br through ATNRC or SET‐NRC at room temperature to afford polymer‐modified graphene, G‐PIB. SET‐NRC method has a faster coupling rate using cheaper reagent (Cu wire instead of CuBr) in comparison with ATNRC approach. Detailed characterizations including FT‐IR, Raman, 1H NMR, TGA, AFM, and TEM assured us of successful anchoring of PIB chains onto the surface of graphene sheets. The resulting G‐PIB nanocomposites still maintain the separated single layers in dispersion and the dispersibilities in organic solvents are significantly improved. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4505–4514

Facile synthesis of polyester dendrimer via combining thio‐bromo “Click” chemistry and ATNRC

“…After a predetermined period of time, excessive DHP‐TEMPO was added to stop the polymerization and PS‐2OH was formed as TEMPO groups capturing the PS macroradicals via ATNRC. It has been proven that ATNRC can rapidly proceed with quantitative conversation, possessing the attributes of “Click” reaction . From Figure , it can be seen that the molecular weight of the PS support did not increase during the 2 h after adding DHP‐TEMPO.…”

“…It is noteworthy that purification of the resulting copolymers only required a simple precipitation utilizing the difference in solubility between PEG conjugated copolymers and the growing units . In present study, a novel efficient approach to rapid synthesis of polyester dendrimer was developed via combination of thio‐bromo “Click” chemistry with ATNRC coupling, as shown in Scheme . Using PS‐2OH as support, dendrimer PTP was divergently grown from the end hydroxyl groups through the acylation and thio‐bromo “Click” reaction two‐step process.…”

Post‐polymerization modification by nitroxide radical coupling

“…Later, MWCNT‐ g ‐PS was obtained by coupling PS with bromine end groups (PS‐Br) onto MWCNTs through the ATNRC reaction using CuBr/ N , N , N ′, N ″, N ″‐pentamethyldiethylenetriamine (PMDETA) as the catalytic system to generate the carbon‐centered radicals. Similarly, ATNRC was successfully used to graft poly( N ‐isopropylacrylamide) or poly(isobutylene) (PIB) on graphene sheets and to prepare polymer clay nanocomposites …”

Marrying mussel inspired chemistry with SET‐LRP: A novel strategy for surface functionalization of carbon nanotubes

“…As compared with classic ATRP, SET‐LRP should be an alternative controlled LRP, which can be occurred at room temperature, atmosphere and aqueous solution with rapid polymerization rate . Given these advantages, SET‐LRP has rapidly attracted great research attention and explored for various applications including the surface modification of carbon nanomaterials …”