Synthesis of novel amphiphilic polymer-coated magnetite dispersion

Abstract

Poly (N-(2-hydroxyethyl)maleimide-co-1-octadecene) and poly(maleic anhydride-co-1-octadecene) (PMAO) were synthesized by reversible additionfragmentation chain transfer (RAFT) polymerization using S-1-dodecyl-S′-(α,α′- dimethyl-α′′-acetic acid) trithiocarbonate and S-1-dodecyl-S′-(α,α′-dimethyl-α′′- methyl acetate) trithiocarbonate as RAFT transfer agents, respectively. PMAO was further modified at maleic anhydride moiety via ring opening followed by coupling reaction of the generated carboxylic acid with 2-(2-aminoethoxy)ethanol, to obtain the PMAO derivative. Monodispersed magnetite nanoparticles with different particle sizes, 11-32 nm, were prepared by thermal decomposition of iron(III) hydroxide oxide with various the oleic acid concentration. The formation of magnetite complex dispersion was generated by mixing the polymer solution and the 11 nm monodispersed magnetite solution, followed by adding water, and removing the organic solvent from the mixture. Whereas the resulting magnetite complex using PMAO derivative appeared as a clear solution, the precipitation was observed in case of using poly (N-(2-hydroxyethyl)maleimide-co-1-octadecene). In addition, the first solution was found to be the dispersion of nanoparticles with the average size of 13 nm as revealed by TEM. These results indicated that a novel amphiphilic polymercoated magnetite dispersion was successfully synthesized. All copolymers were characterized by ATR-IR, ¹H-NMR, ¹³C-NMR, GPC and TGA.