Multiwalled carbon nanotubes grafted with hyperbranched polymer shell via SCVP

A self-condensing vinyl polymerization (SCVP) strategy via atom transfer radical polymerization (ATRP) was employed to grow hyperbranched macromolecules on the surfaces of multiwalled carbon nanotubes (MWNTs). The MWNT surface fixed with ATRP initiators [MWNT-COOCH2CH2OCOC(CH3)(2)Br, MWNT-Br] was prepared by reaction of MWNT-COCl with excess of 2-hydroxyethyl 2'-bromoisobutyrate. Then, using the MWNT-Br as polyfunctional initiator (B-f*), hyperbranched macromolecules were covalently grafted on MWNTs by self-condensing vinyl polymerization of 2-((bromobutyryl)oxy)ethyl acrylate (BBEA, AB* inimer) via the ATRP process. The resultant products were characterized by FT-IR, NMR, and TEM. TGA measurements showed that the weight ratio of the as-grown hyperbranched polymers on the MWNT surfaces reached 80%. The as-prepared MWNTs grafted with hyperbranched polymers exhibit relatively good dispersibility in organic solvents such as THF and chloroform.