scholarly journals Thermo/pH Responsive Star and Linear Copolymers Containing a Cholic Acid-Derived Monomer, N-Isopropylacrylamide and Acrylic Acid: Synthesis and Solution Properties

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1859 ◽  
Author(s):  
Ana Castro-Hernández ◽  
Norma Aidé Cortez-Lemus
Keyword(s):  
Transition Temperature ◽  
Acrylic Acid ◽  
Cholic Acid ◽  
Raft Polymerization ◽  
Acid Synthesis ◽  
Block Sequence ◽  
Controlled Polymerization ◽  
Ph Values ◽  
Time Period ◽  
Reversible Addition

In this work three CTAs trithiocarbonate-type were synthesized—bifunctional (with PEG), trifunctional (with glycerol), and tetrafunctional (PERT)—and used in the controlled polymerization of 2-(acryloyloxy)ethyl cholate (CAE) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The resulting macroCTAs containing a cholic acid-derived polymer were chain extended with N-isopropylacrylamide with or without acrylic acid. The thermosensitive and/or pH properties of these copolymers were studied in PBS solutions. The copolymers synthesized without poly(acrylic acid) (PAAc) were unstable above the transition temperature. Similar behavior was observed for the copolymer solutions containing PAAc (2% in feed) at lower values of pH showing a faster precipitation above the LCST. On the contrary, copolymer solutions containing PAAc showed great stability at higher pH values for a longer time period at 37 °C. Interestingly, the Dh of the aggregates ranged from 18 to 30 nm in all copolymers (with or without PAAc) below the transition temperature, although the topology and the block sequence in the chain were significantly different.

scholarly journals Controlling the block sequence of multi-block oligomer ligands for neutralization of a target peptide

2020 ◽  
Vol 1 (4) ◽  
pp. 604-608
Author(s):  
Hinata Takimoto ◽  
Sho Katakami ◽  
Yoshiko Miura ◽  
Yu Hoshino
Keyword(s):  
Chain Transfer ◽  
Raft Polymerization ◽  
Block Sequence ◽  
Affinity Ligands ◽  
Target Peptide ◽  
Monomer Composition ◽  
High Affinity ◽  
Reversible Addition

A series of block oligomers consisting of the same monomer composition but a different block sequence was prepared via reversible addition–fragmentation chain transfer (RAFT) polymerization to screen high affinity ligands for a toxic peptide.

scholarly journals A well-defined polyelectrolyte and its copolymers by reversible addition fragmentation chain transfer (RAFT) polymerization: synthesis and applications

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98559-98565 ◽  
Author(s):  
Muhammad Mumtaz ◽  
Karim Aissou ◽  
Dimitrios Katsigiannopoulos ◽  
Cyril Brochon ◽  
Eric Cloutet ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Self Assembly ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Controlled Polymerization ◽  
Reversible Addition ◽  
Block Copolymer Electrolytes

Controlled polymerization and self-assembly of novel block copolymer electrolytes.

High Temperature Initiator-Free RAFT Polymerization of Methyl Methacrylate in a Microwave Reactor

2009 ◽  
Vol 62 (3) ◽  
pp. 254 ◽  
Author(s):  
Renzo M. Paulus ◽  
C. Remzi Becer ◽  
Richard Hoogenboom ◽  
Ulrich S. Schubert
Keyword(s):  
High Temperature ◽  
Methyl Methacrylate ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Linear Increase ◽  
Thermal Heating ◽  
Controlled Polymerization ◽  
Microwave Reactor ◽  
Reversible Addition ◽  
Raft Agent

The reversible addition–fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) was investigated under microwave irradiation. At first, a comparison was made between microwave and thermal heating for the RAFT polymerization of MMA with azobis(isobutyronitrile) (AIBN) as initiator and 2-cyano-2-butyldithiobenzoate (CBDB) as RAFT agent, revealing comparable polymerization kinetics indicating the absence of non-thermal microwave effects. Second, the CBDB-mediated RAFT polymerization of MMA was investigated at high temperatures (120°C, 150°C, and 180°C, respectively) in the absence of a radical initiator, showing a linear increase of the molar masses with conversion. The polydispersity indices remained below 1.5 up to 25% MMA conversion at 120°C and 150°C, indicating a controlled polymerization. This control over the polymerization was confirmed by the ability to control the molar masses by the concentration of RAFT agent.

scholarly journals Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

2016 ◽  
Vol 7 ◽  
pp. 2000-2012 ◽  
Author(s):  
Dessislava Kostadinova ◽  
Ana Cenacchi Pereira ◽  
Muriel Lansalot ◽  
Franck D’Agosto ◽  
Elodie Bourgeat-Lami ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Electrostatic Interactions ◽  
Interlayer Space ◽  
Raft Polymerization ◽  
Exchange Process ◽  
Random Copolymers ◽  
Reversible Addition ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Structural Aspects

Increasing attention has been devoted to the design of layered double hydroxide (LDH)-based hybrid materials. In this work, we demonstrate the intercalation by anion exchange process of poly(acrylic acid) (PAA) and three different hydrophilic random copolymers of acrylic acid (AA) and n-butyl acrylate (BA) with molar masses ranging from 2000 to 4200 g mol−1 synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, into LDH containing magnesium(II) and aluminium(III) intralayer cations and nitrates as counterions (MgAl-NO3 LDH). At basic pH, the copolymer chains (macroRAFT agents) carry negative charges which allowed the establishment of electrostatic interactions with the LDH interlayer and their intercalation. The resulting hybrid macroRAFT/LDH materials displayed an expanded interlamellar domain compared to pristine MgAl-NO3 LDH from 1.36 nm to 2.33 nm. Depending on the nature of the units involved into the macroRAFT copolymer (only AA or AA and BA), the intercalation led to monolayer or bilayer arrangements within the interlayer space. The macroRAFT intercalation and the molecular structure of the hybrid phases were further characterized by Fourier transform infrared (FTIR) and solid-state 13C, 1H and 27Al nuclear magnetic resonance (NMR) spectroscopies to get a better description of the local structure.

scholarly journals Miniemulsion RAFT Copolymerization of MMA with Acrylic Acid and Methacrylic Acid and Bioconjugation with BSA

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 828 ◽  
Author(s):  
Débora Vieira Way ◽  
Rayany Stôcco Braido ◽  
Sabrina Alves dos Reis ◽  
Flávio Alves Lara ◽  
José Carlos Pinto
Keyword(s):  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Methacrylic Acid ◽  
Raft Polymerization ◽  
Polymer Nanoparticles ◽  
Cell Uptake ◽  
Copolymer Composition ◽  
Reversible Addition ◽  
Complex Architectures ◽  
Raft Agent

Polymerization through reversible addition-fragmentation chain-transfer (RAFT) polymerization has been extensively employed for the production of polymers with controlled molar mass, complex architectures and copolymer composition distributions intended for biomedical and pharmaceutical applications. In the present work, RAFT miniemulsion copolymerizations of methyl methacrylate with acrylic acid and methacrylic acid were conducted to prepare hydrophilic polymer nanoparticles and compare cell uptake results after bioconjugation with bovine serum albumin (BSA), used as a model biomolecule. Obtained results indicate that the RAFT agent 2-cyano-propyl-dithiobenzoate allowed for successful free radical controlled methyl methacrylate copolymerizations and performed better when methacrylic acid was used as comonomer. Results also indicate that poly(methyl methacrylate-co-methacrylic acid) nanoparticles prepared by RAFT copolymerization and bioconjugated with BSA were exceptionally well accepted by cells, when compared to the other produced polymer nanoparticles because cellular uptake levels were much higher for particles prepared in presence of methacrylic acid, which can probably be associated to its high hydrophilicity.

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

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...

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

Polymers ◽  
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.

scholarly journals Novel Preparation of Noncovalent Modified GO Using RAFT Polymerization to Reinforce the Performance of Waterborne Epoxy Coatings

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 348 ◽  
Author(s):  
Baolei Liu ◽  
Mingqian Wang ◽  
Ying Liang ◽  
Zhicheng Zhang ◽  
Guohong Ren ◽  
...  
Keyword(s):  
Raft Polymerization ◽  
Salt Spray ◽  
Thermo Gravimetric Analysis ◽  
Analytical Techniques ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Block Polymer ◽  
Reversible Addition ◽  
Waterborne Epoxy ◽  
And Performance

This work launches the first-ever report on the fabrication of waterborne epoxy-graphene oxide (GO) coatings (WEGC) using a block polymer as a dispersant of GO, wherein the block polymer was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylic acid and oligo(ethylene glycol) methyl ether methacrylate A number of analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and salt spray tests, were utilized to explore the morphology and performance of the WEGC. It was confirmed that POEGMA950-b-PAA attached to the GO nanosheets, increasing the integral space of the sheets. Modified GO (MGO) layers were well-dispersed in the epoxy matrix through the formation of a GO-dispersant-epoxy ternary molecular structure. Furthermore, the presence of MGO substantially influenced the thermal properties, mechanical properties, and anticorrosion performance of the WEGC. TGA, salt spray tests, and pull-off testsshowed that 0.5 wt.% MGO content achieved the greatest improvement in the evaluated properties.

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.

Living Radical Polymerization with Reversible Addition−Fragmentation Chain Transfer (RAFT Polymerization) Using Dithiocarbamates as Chain Transfer Agents

1999 ◽  
Vol 32 (21) ◽  
pp. 6977-6980 ◽  
Author(s):  
Roshan T. A. Mayadunne ◽  
Ezio Rizzardo ◽  
John Chiefari ◽  
Yen Kwong Chong ◽  
Graeme Moad ◽  
...  
Keyword(s):  
Radical Polymerization ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Living Radical Polymerization ◽  
Reversible Addition ◽  
Transfer Agents
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