The ambient temperature (20°C) reversible addition fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) conducted directly in aqueous media under γinitiation (at dose rates of 30 Gy·h-1) proceeds in a controlled fashion (typically, M̄w/M̄n < 1.2) to near quantitative conversions and up to number-average molecular weights of 2.5 × 105 g·mol-1 for PNIPAAm and 1.1 × 105 g·mo-1 for PAA via two water-soluble trithiocarbonate chain transfer agents, i.e., S,S-bis(α,α′- dimethyl-α″-acetic acid)trithiocarbonate (TRITT) and 3-benzylsulfanyltbiocar-bonylsulfanyl propionic acid (BPATT). The generated polymers are successfully chain extended, which suggests that the RAFT agents are stable throughout the polymerization process so that complex and well-defined architectures can be obtained.
- Acrylic acid
- Kinetics (polym.)
- Reversible addition fragmentation chain transfer (RAFT)
- Smart polymers