Synthesis of Novel Amphiphilic and pH-Sensitive ABC Miktoarm Star Terpolymers

Abstract

Novel amphiphilic ABC miktoarm star terpolymers were synthesized that consist of hydrophilic poly(ethylene oxide) (PEO), hydrophobic poly( -caprolactone) (PCL), and pH-sensitive poly(2-vinylpyridine) (P2VP), thus a water-soluble block upon protonation. In the first step, poly(ethylene oxide monomethyl ether) (MPEO) was capped by one ω-epoxy end group by reaction of the original hydroxy end group with epichlorohydrin. MPEO-b-P2VP diblock copolymers were prepared by nucleophilic addition of living P2VP -Li + chains onto the epoxy group of MPEO's. Finally, the hydroxy group formed at the junction of the MPEO and P2VP blocks was used to initiate the ring-opening polymerization of -caprolactone in the presence of tin octoate. The ABC starshaped triblocks were characterized by 1 H NMR spectroscopy and size exclusion chromatography.

A cyclodextrin-core star copolymer with Y-shaped ABC miktoarms and its unimolecular micelles

“…The synthesis procedure of PEG(-alkynyl)-PDEA is shown in Scheme 1c-g. Firstly, a-methoxy-u-epoxypoly(ethylene oxide) (mPEG-epoxide) was synthesized by the reaction of the hydroxyl group at the end of mPEG with epichlorohydrin in the presence of NaH (see Scheme 1c). 34,35 The 1 H NMR spectrum of mPEGepoxide is shown in ESI, Fig. S3.…”

Silver Metallic Cyclodextrin‐Core Star mPEG

“…The synthesis procedure of mPEG(‐aldehyde)‐alkynyl ( II ) is shown in Scheme c–e. First, mPEG‐epoxide was synthesized by the reaction of the end hydroxyl group of mPEG with epichlorohydrin in the presence of NaH (Scheme c) . In 1 H NMR spectrum of mPEG‐epoxide (Figure S2a, Supporting Information), the resonances at δ = 3.70 and 3.40 ppm are assigned to the protons of –O CH 2 CH 2 O‐ and –O CH 3 groups of the mPEG, respectively; the peaks at δ = 3.18, 2.81, and 2.63 are assigned to the resonances of the end epoxy group added .…”

Macromolecular engineering and stimulus response in the design of advanced drug delivery systems

“…The synthetic strategies have been detailed elsewhere. [27][28][29] Special attention has been paid to the micelle formation of these copolymers in relation to their composition and to the pH of the dispersion medium (Figure 8). At pH > 7, PCL and nonprotonated P2VP are expected to form the hydrophobic core of the micelles surrounded by a shell of solvated PEO.…”