Polycaprolactone-b-poly(N-isopropylacrylamide) nanoparticles: Synthesis and temperature induced coacervation behavior

Poly(caprolactone)-b-poly(N-isopropylacrylamide) (PCL-b-PNIPAM) copolymers were prepared with different compositions of the individual blocks using a combination of enzyme catalyzed anionic ring opening (AROP) polymerization, reversible addition fragmentation chain transfer (RAFT) polymerization and triazolinedionediene click chemistry. Study of the self-assembly of these block copolymers at different temperatures demonstrates the formation of nanoparticles, characterized by a thermo-responsive behavior that is strongly dependent on the PNIPAM block length. At elevated temperature, self-aggregation (coacervation) of the nanoparticles could occur, leading to the formation of larger polymer aggregates.