ma8b00949_si_001.pdf (4.25 MB)
3‑Miktoarm Star Terpolymers via Janus Polymerization: One-Step Synthesis and Self-Assembly
journal contribution
posted on 2018-06-22, 14:55 authored by Yao Li, Moritz von der Lühe, Felix H. Schacher, Jun LingJanus
polymerization combines cationic and anionic polymerizations
into the two ends of a single growing chain and presents a novel pathway
to produce topologically defined polymers. In this contribution, we
report a one-step synthesis of 3-miktoarm star terpolymers of poly(ethylene
glycol)-star-poly(ε-caprolactone)-star-poly(ε-caprolactone-co-tetrahydrofuran) (PEG-star-PCL-star-P(CL-co-THF))
via Janus polymerization using lutetium triflates (Lu(OTf)3) and methoxypoly(ethylene glycol) epoxy (mPEG-EO) as catalyst
and macroinitiator, respectively. Self-assembly of PEG-star-PCL-star-P(CL-co-THF)
into vesicles in aqueous solution depends on the ratio of hydrophilic
and hydrophobic block of the terpolymers. Coassembly of the terpolymer
with a PCL homopolymer (MW = 3000), on the other hand, increases shell
thickness and vesicle diameter. Furthermore, nanorods and needle-shaped
aggregates featuring high aspect ratios are obtained upon self-assembly
at an interface. This unique behavior can be attributed to crystallization
of the PCL segments. Based on the biocompatible and biodegradable
nature of the constituting segments, the herein described 3-miktoarm
star terpolymers might be promising materials for drug/gene delivery
or as bionanoreactors, especially as wall thickness and stiffness
of the structures observed can be tuned. With that control over (nano)local
permeability might be feasible.