Synthesis of PPEGMEA-g-PMAA densely grafted double hydrophilic copolymer and its use as a template for the preparation of size-controlled superparamagnetic Fe3O4/polymer nano-composites

Abstract

A series of well-defined amphiphilic densely grafted copolymers, containing polyacrylate backbone, hydrophobic poly(methoxymethyl methacrylate) and hydrophilic poly(ethylene glycol) side chains, were synthesized by successive atom transfer radical polymerization. Poly[poly(ethylene glycol) methyl ether acrylate] comb copolymer was firstly prepared via the grafting-through strategy. Next, poly[poly(ethylene glycol) methyl ether acrylate]-g-poly(methoxymethyl methacrylate) amphiphilic graft copolymers were synthesized via the grafting-from route. Poly(methoxymethyl methacrylate) side chains were connected to the polyacrylate backbone through stable C-C bonds instead of ester connections. The molecular weights of both the backbone and the side chains were controllable and the molecular weight distributions were in the range 1.38-1.42. Poly(methoxymethyl methacrylate) side chains were selectively hydrolyzed under mild conditions without affecting the polyacrylate backbone to obtain the final product, poly[poly(ethylene glycol) methyl ether acrylate]-g-poly(methacrylic acid) densely grafted double hydrophilic copolymer. Finally, these double hydrophilic copolymers were used as templates to prepare superparamagnetic Fe 3 O 4 /polymer nano-composites with narrow size distributions via an in situ co-precipitation process, which were characterized by FT-IR, TGA, DLS and X-ray diffraction in detail. The size of the nano-composites can be controlled in a certain range by adjusting the length of the poly(methacrylic acid) side chains and the weight ratio of copolymer to Fe 3 O 4 nano-particle used.

PEGylated Inorganic Nanoparticles

“…Graft copolymerization of PEGMEA (PEG-methyl ether acrylate) with polymethyl methacrylate using atom transfer radical polymerization have been used to synthesize MIPs in PPEGMEA-PMMA by co-precipitation of Fe 2+ and Fe 3+ in the presence of polymer. [93] The surface charge was shielded effectively as a function of increase in PMMA side-chain length. MIPs were also synthesized directly in antibiofouling polymer TMSMA (trimethoxysilyl propyl methacrylate) linked to PEG and silane.…”

“…Direct synthesis of oxide nanoparticles in PEG can also lead to direct PEGylation through the formation of M-O-C bonds as has been reported for cerium oxide, iron oxide, as well as silica NPs. [21,43,92,93] The use of functional PEG terminating in OH and COOH groups or grafted with copolymers, such as PEI (polyethylene imine), [94] PMMA (polymethyl methacrylate), [93] PAMAM (polyamido amine), [95] has also been reported.…”

Methods of controlled radical polymerization for the synthesis of polymer brushes

“…It should be noted that the direct ATRP of (meth)acrylic acid is impossible because of catalyst poisoning. Therefore, precursors, for example, poly(tert butyl(meth)acrylate) or poly(methoxyme thyl methacrylate), are initially synthesized and then transformed into the corresponding acid via acidic hydrolysis [31,32,149].…”

“…Polymer brushes with polyacids in side chains can change their conformations, depending on the pH and ionic strength of solvent, to form complexes with tran sition metals [5] and to incorporate macromolecules, complexes, or nanoparticles [138,149]. Investigations of such composites are one of the promising and actively developing lines of research.…”

“…Investigations of such composites are one of the promising and actively developing lines of research. In [149], a com posite based on Fe 3 O 4 nanoparticles and a multigrafted brush with poly(methacrylic acid) (PMAA) side chains was obtained and its magnetic properties were investigated. No.…”