Graft modification of lignin-based cellulose via enzyme-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization and free-radical coupling

We compared the influence of the polymerization mechanism onto the physical characteristics of thermoresponsive hydrogels. The Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels were successfully synthesized using reversible addition-fragmentation chain-transfer (RAFT) and free radical polymerization (FRP). The gels were prepared while using different crosslinker feed and monomer concentration. The swelling, dye release, and hydrolytic stability of the gels were investigated in water, or in representative komostrope and chaotrope salt solutions at room temperature and at 37 °C. It was found that the swelling ratio (SR) of the RAFT gels was significantly higher than that of the FRP gels; however, an increased crosslinking density resulted in a decrease of the SR of the RAFT gels as compared to the corresponding gels that are made by FRP, which indicates the limitation of the cross-linking efficiency that is attained in RAFT polymerization. Additionally, an increased monomer concentration decreased the SR of the RAFT gels, whereas a similar SR was observed for the FRP gels. However, the SR of both RAFT and FRP gels in NaSCN and Na2SO4 solutions were similar. Finally, the rate of dye release was significantly slower from the RAFT gels than the FRP gels and the hydrolytic stability of the RAFT gels was lower than that of FRP gels in water, but maintained similar stability in Na2SO4 and NaSCN solutions.

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Thiocarbonylthio Compounds (SC(Z)S−R) in Free Radical Polymerization with Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization). Effect of the Activating Group Z

Macromolecules ◽

10.1021/ma020883+ ◽

2003 ◽

Vol 36 (7) ◽

pp. 2273-2283 ◽

Cited By ~ 396

Author(s):

John Chiefari ◽

Roshan T. A. Mayadunne ◽

Catherine L. Moad ◽

Graeme Moad ◽

Ezio Rizzardo ◽

...

Keyword(s):

Free Radical ◽

Radical Polymerization ◽

Chain Transfer ◽

Raft Polymerization ◽

Free Radical Polymerization ◽

Reversible Addition

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A New Method in Improving RAFT Polymerization Rate of Styrene

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.482-484.1886 ◽

2012 ◽

Vol 482-484 ◽

pp. 1886-1889

Author(s):

Qing Bo Yu ◽

Xian Hua Li

Keyword(s):

Free Radical ◽

Radical Polymerization ◽

Chain Transfer ◽

Raft Polymerization ◽

Free Radical Polymerization ◽

Polymerization Rate ◽

New Method ◽

Continuous Polymerization ◽

Reversible Addition ◽

Living Free Radical Polymerization

A batch reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene was investigated. The results show that the process has good characteristics of living free radical polymerization. The polymerization rate is higher comparing continuous polymerization.

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Self-Healing Hydrophobic POSS-functionalized Fluorinated Copolymer via RAFT Polymerization and dynamic Diels-Alder Reaction

Polymer Chemistry ◽

10.1039/d0py01522a ◽

2021 ◽

Author(s):

Siva Ponnupandian ◽

Prantik Mondal ◽

Thomas Becker ◽

Richard Hoogenboom ◽

Andrew B Lowe ◽

...

Keyword(s):

Chain Transfer ◽

Raft Polymerization ◽

Alder Reaction ◽

Diels Alder ◽

Self Healing ◽

Diels Alder Reaction ◽

Reversible Addition

This investigation reports the preparation of a tailor-made copolymer of furfuryl methacrylate (FMA) and trifluoroethyl methacrylate (TFEMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The furfuryl groups of the copolymer...

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Nano-Assemblies from Amphiphilic PnBA-b-POEGA Copolymers as Drug Nanocarriers

Polymers ◽

10.3390/polym13071164 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1164

Author(s):

Angeliki Chroni ◽

Thomas Mavromoustakos ◽

Stergios Pispas

Keyword(s):

Molecular Weight ◽

Chain Transfer ◽

Raft Polymerization ◽

Polymeric Nanocarriers ◽

Reversible Addition ◽

2D Noesy ◽

Drug Nanocarriers ◽

Glycol Methyl Ether ◽

Different Molecular Weight

The focus of this study is the development of highly stable losartan potassium (LSR) polymeric nanocarriers. Two novel amphiphilic poly(n-butyl acrylate)-block-poly(oligo(ethylene glycol) methyl ether acrylate) (PnBA-b-POEGA) copolymers with different molecular weight (Mw) of PnBA are synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by the encapsulation of LSR into both PnBA-b-POEGA micelles. Based on dynamic light scattering (DLS), the PnBA30-b-POEGA70 and PnBA27-b-POEGA73 (where the subscripts denote wt.% composition of the components) copolymers formed micelles of 10 nm and 24 nm in water. The LSR-loaded PnBA-b-POEGA nanocarriers presented increased size and greater mass nanostructures compared to empty micelles, implying the successful loading of LSR into the inner hydrophobic domains. A thorough NMR (nuclear magnetic resonance) characterization of the LSR-loaded PnBA-b-POEGA nanocarriers was conducted. Strong intermolecular interactions between the biphenyl ring and the butyl chain of LSR with the methylene signals of PnBA were evidenced by 2D-NOESY experiments. The highest hydrophobicity of the PnBA27-b-POEGA73 micelles contributed to an efficient encapsulation of LSR into the micelles exhibiting a greater value of %EE compared to PnBA30-b-POEGA70 + 50% LSR nanocarriers. Ultrasound release profiles of LSR signified that a great amount of the encapsulated LSR is strongly attached to both PnBA30-b-POEGA70 and PnBA27-b-POEGA73 micelles.

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

Canadian Journal of Chemistry ◽

10.1139/v10-134 ◽

2011 ◽

Vol 89 (3) ◽

pp. 317-325 ◽

Cited By ~ 10

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.

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