Synthesis ABA Triblock Copolymers by Complex Living Free Radical Polymerization

Triblock copolymers, methyl methacrylate-isoprene-methyl methacrylate (MIM), was successfully synthesized via anionic living polymerization (ALP) following the novel mercaptan/ε-caprolactam living polymerization (MLP) at low... [ view full abstract ]

Triblock copolymers, methyl methacrylate-isoprene-methyl methacrylate (MIM), was successfully synthesized via anionic living polymerization (ALP) following the novel mercaptan/ε-caprolactam living polymerization (MLP) at low reaction temperature. The MLP overcame that the severe polymerization conditions of acrylate monomer is needed in anionic living polymerization. Molecular weight of each segment in MIM was identified by using GPC and ¹H-NMR instrument, respectively. Mw of isoprene and methyl methacrylate segments of MIM are in the range of 10,000~20,000 and 60,000~140,000, respectively. PDI of isoprene segment and MIM are located at 1.10 and 1.20~ 1.80, respectively. Two glass transition temperature (T_g), - 60℃~ -8.5℃ for isoprene domain and 115℃ for methyl methacrylate domain, of MIM was clearly presented on the DSC curve, which reveals the completely immiscible between PI and PMMA domains. This result also can be confirmed by TEM micrographs. In TEM pictures, regularly phase domain pattern was formed via self-assembled of polymer chains without annealing treatment. This phase diagram of MIM material has highly potential applied on biomaterial research in future.