Solid-supported synthesis of well-defined amphiphilic block copolymer from methacrylates

Abstract

A new facile method for preparation of an amphiphilic block copolymer via a one-pot sequential atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) on solid support was developed. As a model homopolymerization for the solid-supported block copolymerization, ATRPs of MMA and HEMA in toluene and in 2-butanone/1-propanol solvent system were carried out, respectively. Crosslinked polystyrene beads bearing 2-bromoisobutyrate moieties successfully initiated the polymerizations of MMA and HEMA in controlled manner. On the basis of the successful results, the one-pot synthesis of amphiphilic block copolymer by changing the reaction medium was performed. After the ATRP of MMA in toluene at 90 °C for 1 h, the poly(MMA) formed on the beads were washed by continuous flow of 2-butanone/1-propanol under nitrogen with the aid of a glass filter in a U-shaped glass vessel. Then, 2-butanone/1-propanol, copper chloride (I), 2,2′-bipyridyl, and HEMA were added and heated at 50 °C for 48 h with shaking the vessel, followed by treatment with trifluoroacetic acid to isolate the well-defined amphiphilic block copolymer, poly(MMA-b-HEMA). These demonstrated the feasibility of the present strategy for well-defined synthesis of amphiphilic block copolymers via a one-pot procedure. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1990–1997, 2008