Synthesis of di‐ and tri‐tertiary amine containing methacrylic monomers and their (co)polymerization via RAFT

The synthesis, reversible addition‐fragmentation chain transfer (RAFT) (co)polymerization, and aqueous phase behavior of three methacrylic monomers containing two or three pendent tertiary amine functional groups are described. Homopolymerizations were conducted with 1‐methyl‐1‐cyanoethyl dithiobenzoate (CPDB) under bulk conditions following standard RAFT procedures. All three monomers, 1,3‐bis(dimethylamino)propan‐2‐yl methacrylate ( M1 ), 1‐(bis(3‐(dimethylamino)propyl) amino)propan‐2‐yl methacrylate ( M2 ), and 2‐((2‐(2‐(dimethylamino)ethoxy)ethyl) methylamino)ethyl acrylate ( M3 ), polymerized in a controlled manner as evidenced by the kinetic and molecular weight profiles. Homopolymerizations conducted at a lower ratio of CPDB:AIBN proceeded faster than those at a higher ratio. Subsequently, the facile copolymerization behavior of M1 and M3 was demonstrated via the synthesis of a range of statistical copolymers with hexyl and lauryl methacrylate comonomers containing 10–90 mol % hydrophobic comonomer. Finally, the aqueous‐solution characteristics of the M1 – M3 homopolymers were briefly examined. All three homopolymers were shown to undergo phase transitions in aqueous media in response to changes in both temperature and pH. Specifically, 1 wt % solutions of poly M1 were shown to possess an LCST of ～22 °C, that of poly M2 at ～33 °C, and for poly M3 the observed cloud point was ～63 °C. Additionally, all homopolymers became hydrophobic and phase separated at high solution pH. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1877–1890, 2009