Synthesis of N-vinylcarbazole–N-vinylpyrrolidone amphiphilic block copolymers by xanthate-mediated controlled radical polymerization

2010 ◽  
Vol 88 (3) ◽  
pp. 228-235 ◽  
Author(s):  
Chih-Feng Huang ◽  
Jeong Ae Yoon ◽  
Krzysztof Matyjaszewski
Keyword(s):  
Block Copolymers ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Controlled Radical Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Force Microscopy ◽  
Molecular Weights ◽  
Atomic Force ◽  
Reversible Addition ◽  
Mode Atomic Force Microscopy

Amphiphilic block copolymers poly(N-vinylcarbazole)-b-poly(N-vinylpyrrolidone) (PNVK-b-PNVP) were prepared by xanthate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization. Both the PNVK and PNVP macroinitiators and the resulting block copolymers had molecular weights close to theoretical values, predicted for efficient initiation, in the range of Mn = 30 000 to 90 000. The block copolymers dissolved in several organic solvents but, depending on their composition, in methanol formed either micelles or large aggregates, as confirmed by dynamic light scattering. The presence of globular aggregates was confirmed by tapping mode atomic force microscopy.

scholarly journals Synthesis of Terpyridine-Terminated Amphiphilic Block Copolymers and Their Self-Assembly into Metallo-Polymer Nanovesicles

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 601 ◽  
Author(s):  
Tatyana Elkin ◽  
Stacy Copp ◽  
Ryan Hamblin ◽  
Jennifer Martinez ◽  
Gabriel Montaño ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Efficient Route ◽  
High Yields

Polystyrene-b-polyethylene glycol (PS-b-PEG) amphiphilic block copolymers featuring a terminal tridentate N,N,N-ligand (terpyridine) were synthesized for the first time through an efficient route. In this approach, telechelic chain-end modified polystyrenes were produced via reversible addition-fragmentation chain-transfer (RAFT) polymerization by using terpyridine trithiocarbonate as the chain-transfer agent, after which the hydrophilic polyethylene glycol (PEG) block was incorporated into the hydrophobic polystyrene (PS) block in high yields via a thiol-ene process. Following metal-coordination with Mn2+, Fe2+, Ni2+, and Zn2+, the resulting metallo-polymers were self-assembled into spherical, vesicular nanostructures, as characterized by dynamic light scattering and transmission electron microscopy (TEM) imaging.

Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization of Vinyl Monomers Initiated by Poly(methyl methacrylate) Peroxide

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhengbiao Zhang ◽  
Xiulin Zhu ◽  
Jian Zhu ◽  
Zhenping Cheng
Keyword(s):  
Methyl Methacrylate ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Controlled Radical Polymerization ◽  
Polymer Chains ◽  
Poly Methyl Methacrylate ◽  
Molecular Weights ◽  
H Nmr ◽  
Reversible Addition ◽  
Living Controlled Radical Polymerization

AbstractPoly(methyl methacrylate) peroxide (PMMAP) was synthesized and used as the initiator in the reversible addition-fragmentation chain transfer (RAFT) polymerization. Methyl methacrylate (MMA) as the monomer and 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) as the chain transfer agent was used in the polymerization system. The polymerization was successfully initiated by PMMAP while maintaining features of “living”/controlled radical polymerization such as the number-average molecular weights (Mn) increasing linearly with the monomer conversions and low polydispersity index (PDI) values. The results of 1H NMR and IR spectra confirmed that a small quantity of polymer chains were derived from the PMMAP moieties. The PMMAP can also initiate the RAFT polymerization of styrene (St) and methyl acrylate (MA), and the polymerization proceeded in a “living”/controlled fashion.

Engineering of pH-triggered nanoplatforms based on novel poly(2-methyl-2-oxazoline)-b-poly[2-(diisopropylamino)ethyl methacrylate] diblock copolymers with tunable morphologies for biomedical applications

2021 ◽  
Author(s):  
Peter Černoch ◽  
Alessandro Jäger ◽  
Zulfia Cernochova ◽  
Vladimir Sincari ◽  
Lindomar Calumby Albuquerque ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Ring Opening ◽  
Biomedical Applications ◽  
Diblock Copolymers ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Synthetic Approach ◽  
Ethyl Methacrylate ◽  
Reversible Addition

A two-step synthetic approach via the combination of living cationic ring-opening (CROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization techniques was used to produce novel amphiphilic block copolymers based on...

Controlled RAFT synthesis of polystyrene-b-poly(acrylic acid)-b-polystyrene block copolymers and their self-assembly in an ionic liquid [BMIM][PF6]

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Linping Zheng ◽  
Yun Chai ◽  
Yang Liu ◽  
Puyu Zhang
Keyword(s):  
Ionic Liquid ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Potential Applications ◽  
Increasing Temperature

AbstractThe block copolymer of polystyrene-block-polyacrylate-blockpolystyrene (PSt-PAA-PSt) has been synthesized by reversible addition fragmentation chain-transfer (RAFT) polymerization using S,S′-Bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate (BDATC) as chain transfer agent. Three copolymers form micelles in an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]). The nanostructures of the PSt-PAA-PSt micelles formed in ionic liquid were observed by transmission electron microscopy (TEM). The self-assembled morphologies of the micelles are strongly dependent on the length of PAA block chains when the chain length of PS is fixed. The affinity of PAA chains for water and [BMIM][PF6] reverses with increasing temperature. Research results show that the copolymer with low polydispersity can be obtained by controlling polymerization, and the flexibility of amphiphilic block copolymers for controlling nanostructure in an ionic liquid presents potential applications in many arenas.

Synthesis and characterization of a naphthalimide–dye end-labeled copolymer by reversible addition–fragmentation chain transfer (RAFT) polymerization

2011 ◽  
Vol 89 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Binxin Li ◽  
Daniel Majonis ◽  
Peng Liu ◽  
Mitchell A. Winnik
Keyword(s):  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymer Composition ◽  
Cooh Group ◽  
Agent Based ◽  
Molecular Weights ◽  
Reversible Addition ◽  
Raft Agent ◽  
End Use ◽  
Naphthalimide Dye

We describe the synthesis of an end-functionalized copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-hydroxysuccinimide methacrylate (NMS) by reversible addition–fragmentation chain transfer (RAFT) polymerization. To control the polymer composition, the faster reacting monomer (NMS) was added slowly to the reaction mixture beginning 30 min after initating the polymerization (ca. 16% HPMA conversion). One RAFT agent, based on azocyanopentanoic acid, introduced a –COOH group to the chain at one end. Use of a different RAFT agent containing a 4-amino-1,8-naphthalimide dye introduced a UV–vis absorbing and fluorescent group at this chain end. The polymers obtained had molecular weights of 30 000 and 20 000, respectively, and contained about 30 mol% NMS active ester groups.

scholarly journals Reversible addition fragmentation chain transfer polymerization - RAFT

2004 ◽  
Vol 58 (11) ◽  
pp. 514-520
Author(s):  
Milena Avramovic ◽  
Lynne Katsikas ◽  
Branko Dunjic ◽  
Ivanka Popovic
Keyword(s):  
Radical Polymerization ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
General Structure ◽  
Controlled Radical Polymerization ◽  
Molecular Structures ◽  
Reversible Addition ◽  
Chain Transfer Polymerization

The fundamentals of controlled radical polymerization are presented in this review. The paper focuses on reversible addition fragmentation chain transfer (RAFT) polymerization. The mechanism and specifics of this type of polymerization are discussed, as are the possibilities of synthesizing complex macro-molecular structures. The synthesis and properties of RAFT agents, of the general structure Z-C(=S)-S-R, are presented.

Synthesis of amphiphilic block copolymers based on poly(dimethylsiloxane) via fragmentation chain transfer (RAFT) polymerization

Polymer ◽  
2004 ◽  
Vol 45 (13) ◽  
pp. 4383-4389 ◽  
Author(s):  
Tommy S.C Pai ◽  
Christopher Barner-Kowollik ◽  
Thomas P Davis ◽  
Martina H Stenzel
Keyword(s):  
Block Copolymers ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers

scholarly journals Photo-Responsive Polymersomes as Drug Delivery System for Potential Medical Applications

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5147
Author(s):  
Wanting Hou ◽  
Ruiqi Liu ◽  
Siwei Bi ◽  
Qian He ◽  
Haibo Wang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Block Copolymers ◽  
Drug Delivery System ◽  
Delivery System ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Medical Applications ◽  
Drug Molecules ◽  
Reversible Addition ◽  
Raft Agent

Due to a strong retardation effect of o-nitrobenzyl ester on polymerization, it is still a great challenge to prepare amphiphilic block copolymers for polymersomes with a o-nitrobenzyl ester-based hydrophobic block. Herein, we present one such solution to prepare amphiphilic block copolymers with pure poly (o-nitrobenzyl acrylate) (PNBA) as the hydrophobic block and poly (N,N’-dimethylacrylamide) (PDMA) as the hydrophilic block using bulk reversible addition-fragmentation chain transfer (RAFT) polymerization of o-nitrobenzyl acrylate using a PDMA macro-RAFT agent. The developed amphiphilic block copolymers have a suitable hydrophobic/hydrophilic ratio and can self-assemble into photoresponsive polymersomes for co-loading hydrophobic and hydrophilic cargos into hydrophobic membranes and aqueous compartments of the polymersomes. The polymersomes demonstrate a clear photo-responsive characteristic. Exposure to light irradiation at 365 nm can trigger a photocleavage reaction of o-nitrobenzyl groups, which results in dissociation of the polymersomes with simultaneous co-release of hydrophilic and hydrophobic cargoes on demand. Therefore, these polymersomes have great potential as a smart drug delivery nanocarrier for controllable loading and releasing of hydrophilic and hydrophobic drug molecules. Moreover, taking advantage of the conditional releasing of hydrophilic and hydrophobic drugs, the drug delivery system has potential use in medical applications such as cancer therapy.

scholarly journals Redox-Initiated Reversible Addition–Fragmentation Chain Transfer (RAFT) Polymerization

2019 ◽  
Vol 72 (7) ◽  
pp. 479 ◽  
Author(s):  
Amin Reyhani ◽  
Thomas G. McKenzie ◽  
Qiang Fu ◽  
Greg G. Qiao
Keyword(s):  
Redox Reactions ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Molecular Structures ◽  
Biologically Relevant ◽  
Molecular Weights ◽  
Polymeric Biomaterials ◽  
Reversible Addition ◽  
Wide Range ◽  
Metal Catalyzed

Reversible addition–fragmentation chain transfer (RAFT) polymerization initiated by a radical-forming redox reaction between a reducing and an oxidizing agent (i.e. ‘redox RAFT’) represents a simple, versatile, and highly useful platform for controlled polymer synthesis. Herein, the potency of a wide range of redox initiation systems including enzyme-mediated redox reactions, the Fenton reaction, peroxide-based reactions, and metal-catalyzed redox reactions, and their application in initiating RAFT polymerization, are reviewed. These redox-RAFT polymerization methods have been widely studied for synthesizing a broad range of homo- and co-polymers with tailored molecular weights, compositions, and (macro)molecular structures. It has been demonstrated that redox-RAFT polymerization holds particular promise due to its excellent performance under mild conditions, typically operating at room temperature. Redox-RAFT polymerization is therefore an important and core part of the RAFT methodology handbook and may be of particular importance going forward for the fabrication of polymeric biomaterials under biologically relevant conditions or in biological systems, in which naturally occurring redox reactions are prevalent.

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