Synthesis and Surface Characterization of Well-Defined Amphiphilic Block Copolymers Containing Poly[oligo(ethylene glycol) methacrylate] Segments

Abstract

A series of well-defined amphiphilic block copolymers containing poly[oligo(ethylene glycol) methacrylate] (POEGMA)) segments were synthesized by the sequential anionic copolymerization of styrene and trialkylsilyl-protected oligo(ethylene glycol) methacrylates followed by deprotection. OEGMA monomers possessed terminal OH groups on the pendant side chains and included the esters of ethylene glycol, di(ethylene glycol), and tri(ethylene glycol) to change the polarity of hydrophilic polymethacrylate segments. The corresponding methyl ethers of oligo(ethylene glycol) methacrylates (MOEGMA) were also employed to synthesize the amphiphilic block copolymers of polystyrene (PS) and PMOEGMA. Microphase separated structures of the block copolymers were analyzed by small-angle X-ray scattering (SAXS). The block copolymers containing POEGMA segments displayed strongly segregated lamellar structure with sharp interfaces; however, the PMOEGMA counterparts showed either weakly segregated lamellar or disorder structure...