One-Pot Synthesis of Poly(N-vinylpyrrolidone)-b-poly(ε-caprolactone) Block Copolymers Using a Dual Initiator for RAFT Polymerization and ROP

Abstract

Well-defined amphiphilic poly(N-vinylpyrrolidone)-b-poly(ε-caprolactone) (PVP-b-PCL) block copolymers were synthesized at 30 °C using a hydroxylfunctionalized xanthate reversible addition−fragmentation chain transfer (RAFT) agent, 2-hydroxyethyl 2-(ethoxycarbonothioylthio)propanoate, as a dual initiator for RAFT polymerization and ring-opening polymerization (ROP) in a one-pot procedure. Hydrophilic PCL blocks were first synthesized via the ROP of ε-caprolactone (CL) using diphenyl phosphate as a catalyst followed by the RAFT polymerization of Nvinylpyrrolidone (VP) by the addition of VP and 2,2′-azobis(4-methoxy-2,4dimethylvaleronitrile) (V-70) to the reaction mixture. VP quenched the ROP of CL, and V-70 initiated the RAFT polymerization of VP. The resulting PVP-b-PCL block copolymers showed very narrow molecular weight distributions, indicating that the ROP and RAFT polymerization proceeded independently in a controlled manner. To the best of our knowledge, this one-pot process is the most convenient method for the synthesis of PVP-b-PCL block copolymers. The PVP-b-PCL block copolymers could be labeled fluorescently through a reaction with rhodamine B isothiocyanate in the same pot.

Preparation of hydrophilic PCL nanofiber scaffolds via electrospinning of PCL/PVP-b-PCL block copolymers for enhanced cell biocompatibility

“…In our previous study, a very convenient one-pot procedure for the synthesis of PVP-b-PCL block copolymers at 30 °C was developed, using HECP as a dual initiator for reversible addition-fragmentation chain transfer (RAFT) polymerization and ring opening polymerization (ROP) [13]. Fig.…”

Controlled One‐Pot Synthesis of Polystyrene‐block‐Polycaprolactone Copolymers by Simultaneous RAFT and ROP

“…Li et al devised a synthetic method consisting of simultaneous RAFT and ROP, of styrene and lactide, respectively, to prepare a diblock macromonomer that was subsequently used in a ring‐opening metathesis polymerization “grafting through” reaction to produce double‐brush copolymers. Recently, Youk's group reported the successful one‐pot synthesis of poly(alkyl methacrylate)‐ block ‐polyester and poly(vinylpyrrolidone)‐ block ‐polyester copolymers …”

“…These straightforward strategies were facilitated by hydroxyl‐functional molecules that worked concomitantly as a chain transfer agent (CTA) for RAFT and co‐initiator for ROP. However, there is a fundamental difference between the approaches of Howdle and co‐workers and Li et al and Youk and co‐workers that arises from the addition–fragmentation mechanism; in the former case, the CTA was 2‐(benzylsulfanylthiocarbonylsulfanyl)ethanol (1), of which the alcohol function is part of the Z activating group, whereas the free radical leaving group R is not involved in the ROP. As a consequence, the segments of an AB diblock copolymer will be covalently bound by a trithiocarbonate group situated between A and B. Alternatively, in the synthetic methods of Li and Youk the co‐initiator for ROP is attached to the leaving group R, thus leaving the main CTA moiety at the chain end of the RAFT polymer.…”

Catechol/boronic acid chemistry for the creation of block copolymers with a multi-stimuli responsive junction

“…3 They also possess numerous applications in various domains such as thermoplastic elastomer synthesis, membranes, adhesives, chip conception, lithography, cosmetic and drug delivery system design. [11][12][13] Nevertheless, the second strategy has emerged as an interesting pathway with the introduction in the polymer field of very efficient organic reactions such as amide coupling, urethane ligation [14][15][16] and reactions involved in the Click Chemistry concept. With the huge progress in controlled/living polymerizations (i.e.…”