Synthesis of amphiphilic graft copolymer with hydrophilic poly(acrylic acid) backbone and hydrophobic polystyrene side chains

A series of well-defined amphiphilic graft copolymers consisting hydrophilic poly(acrylic acid) backbones and hydrophobic polystyrene side chains were synthesized by successive atom transfer radical polymerization (ATRP) followed by hydrolysis of poly(methoxymethyl acrylate) (PMOMA) backbone. Grafting-from strategy was employed for the synthesis of graft copolymers with narrow molecular weight distribution. Hydrophobic side chains were connected to the backbone through stable C-C bonds. The backbone can be easily hydrolyzed with HCl without affecting hydrophobic side chains. This family of amphiphilic graft copolymers can form stable micelles in water. The critical micelle concentration was determined by fluorescence spectroscopy. The micellar morphologies and sizes were studied using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The sizes of micelles were dependent on ionic strength, pH value and preparation conditions.