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Advanced Polymeric Functional Materials Using Reversible Deactivation Radical Polymerization Techniques

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Chemistry".

Deadline for manuscript submissions: closed (30 April 2020) | Viewed by 45881

Special Issue Editors


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Guest Editor
CICECO—Aveiro Institute of Materials and Department of Chemistry, University of Aveiro—Campus Santiago, 3810-193 Aveiro, Portugal
Interests: polymers and colloids; polymerization; controlled radical polymerization (RAFT; ATRP); hybrid materials; nanocomposites; preparation and characterization of functional materials

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Guest Editor
Univ Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS UMR 5265, Chemistry, Catalysis, Polymers and Processes (C2P2), 43 Bvd. du 11 Novembre 1918, F-69616 Villeurbanne, France
Interests: polymerizations in dispersed media; organic/inorganic hybrids; colloidal nanocomposites; polymer architectures; sol–gel chemistry

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Guest Editor
Department of Chemical Engineering, Engineering School of Lorena, University of São Paulo, EEL-USP, Lorena 12602-810 SP, Brazil
Interests: polymerizations in dispersed media; organic/inorganic hybrids; colloidal nanocomposites; polymers synthesis

Special Issue Information

Dear Colleagues,

This Special Issue will gather novel research works on Reversible Deactivation Radical Polymerization (RDRP), especially regarding its potential use in developing novel advanced functional materials and putting into perspective both the opportunities for advancement as well as the constraints. The potential use of RDRP is widespread, ranging from (bio)sensing, coatings, and drug and gene delivery to water capture. Hence, papers are sought that discuss the latest research in the area or summarize selected areas of the field, highlighting the constraints for its scale-up whilst advancing possible solutions. The scope of this Special Issue encompasses the synthesis and characterization of polymers used for diverse applications, including polymer chains, gels, polymer nanoparticles, polymer-based nanocomposites and hybrid assemblies, novel architectures, and solutions to help overcome the shortcomings of RDRP. RDRP mechanisms, such as RAFT, ATRP, NMP, and RITP, as well as combinations of them and/or combinations with other mechanisms are of interest.

Of particular interest are new structures and functions resulting from the synthesis of polymeric materials in dispersed media leading to enhanced functionality as well as overcoming the constraints associated with the scale-up of the process.

Prof. Dr. Ana Barros-Timmons
Dr. Elodie Bourgeat-Lami
Prof. Dr. Amilton Martins dos Santos
Guest Editors

Manuscript Submission Information

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Keywords

  • Preparation of advanced functional materials
  • Polymer colloids
  • Polymers for (bio)sensing
  • Polymers for drug delivery and gene transfection
  • Synthetic strategies to overcome the limitations associated with RDRP scale-up constraints
  • Polymers for water harvesting
  • Polymers for energy applications
  • Functional polymer coatings

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Published Papers (12 papers)

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Research

Jump to: Review

18 pages, 1584 KiB  
Article
Introduction of Stilbene Derivatives and Cinnamate Ester Derivatives at the ω-End Groups of Poly(Methyl Methacrylate) Prepared via RAFT Polymerization
by Martyn Dobinson, Philip Hodge and Trevor Wear
Polymers 2020, 12(11), 2449; https://doi.org/10.3390/polym12112449 - 23 Oct 2020
Cited by 2 | Viewed by 2739
Abstract
The capping of “living” poly(methyl methacrylate) (PMMA) and “living” polystyrene (PS), both prepared by the RAFT technique, with various olefins was screened using 19F-NMR spectroscopy. The capping of “living” PMMA with a labeled stilbene was as high as 63% and with certain [...] Read more.
The capping of “living” poly(methyl methacrylate) (PMMA) and “living” polystyrene (PS), both prepared by the RAFT technique, with various olefins was screened using 19F-NMR spectroscopy. The capping of “living” PMMA with a labeled stilbene was as high as 63% and with certain cinnamate esters was essentially quantitative, but the capping of “living” polystyrene with all the olefins investigated was generally poor. Full article
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14 pages, 2453 KiB  
Article
Grafting with RAFT—gRAFT Strategies to Prepare Hybrid Nanocarriers with Core-shell Architecture
by José L. M. Gonçalves, Edgar J. Castanheira, Sérgio P. C. Alves, Carlos Baleizão and José Paulo Farinha
Polymers 2020, 12(10), 2175; https://doi.org/10.3390/polym12102175 - 23 Sep 2020
Cited by 12 | Viewed by 3966
Abstract
Stimuli-responsive polymer materials are used in smart nanocarriers to provide the stimuli-actuated mechanical and chemical changes that modulate cargo delivery. To take full advantage of the potential of stimuli-responsive polymers for controlled delivery applications, these have been grafted to the surface of mesoporous [...] Read more.
Stimuli-responsive polymer materials are used in smart nanocarriers to provide the stimuli-actuated mechanical and chemical changes that modulate cargo delivery. To take full advantage of the potential of stimuli-responsive polymers for controlled delivery applications, these have been grafted to the surface of mesoporous silica particles (MSNs), which are mechanically robust, have very large surface areas and available pore volumes, uniform and tunable pore sizes and a large diversity of surface functionalization options. Here, we explore the impact of different RAFT-based grafting strategies on the amount of a pH-responsive polymer incorporated in the shell of MSNs. Using a “grafting to” (gRAFT-to) approach we studied the effect of polymer chain size on the amount of polymer in the shell. This was compared with the results obtained with a “grafting from” (gRAFT-from) approach, which yield slightly better polymer incorporation values. These two traditional grafting methods yield relatively limited amounts of polymer incorporation, due to steric hindrance between free chains in “grafting to” and to termination reactions between growing chains in “grafting from.” To increase the amount of polymer in the nanocarrier shell, we developed two strategies to improve the “grafting from” process. In the first, we added a cross-linking agent (gRAFT-cross) to limit the mobility of the growing polymer and thus decrease termination reactions at the MSN surface. On the second, we tested a hybrid grafting process (gRAFT-hybrid) where we added MSNs functionalized with chain transfer agent to the reaction media containing monomer and growing free polymer chains. Our results show that both modifications yield a significative increase in the amount of grafted polymer. Full article
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16 pages, 6151 KiB  
Article
Grafting Poly(Methyl Methacrylate) (PMMA) from Cork via Atom Transfer Radical Polymerization (ATRP) towards Higher Quality of Three-Dimensional (3D) Printed PMMA/Cork-g-PMMA Materials
by Paula S. S. Lacerda, Nuno Gama, Carmen S. R. Freire, Armando J. D. Silvestre and Ana Barros-Timmons
Polymers 2020, 12(9), 1867; https://doi.org/10.3390/polym12091867 - 19 Aug 2020
Cited by 17 | Viewed by 4112
Abstract
Cork is a unique material and its by-products are attracting an ever-growing interest for preparing new materials in an attempt to extend the outstanding properties of cork toward innovative and high value applications. Yet, the miscibility of cork particles with thermoplastic matrices is [...] Read more.
Cork is a unique material and its by-products are attracting an ever-growing interest for preparing new materials in an attempt to extend the outstanding properties of cork toward innovative and high value applications. Yet, the miscibility of cork particles with thermoplastic matrices is not easy due to its low density and surface properties. Here, cork is functionalized with poly(methyl methacrylate) (PMMA) via atom transfer radical polymerization (ATRP) to yield cork grafted with PMMA chains particles (cork-g-PMMA). Both the ATRP macroinitiator and the cork-g-PMMA obtained are fully characterized by Fourier-transform infrared spectroscopy (FT-IR), 13C cross-polarized magic-angle spinning solid-state nuclear magnetic resonance (13C CP/MAS solid state NMR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD) and thermogravimetric analyses (TGA). The functionalized cork particles are then blended with commercial PMMA to afford cork-g-PMMA/PMMA. To compare, cork also is mixed with PMMA and the ensuing cork/PMMA sample and its morphology, thermal, and mechanical properties are compared with those of cork-g-PMMA/PMMA and commercial PMMA. The cork surface modification via ATRP of the methyl methacrylate (MMA) yields better dispersion in the matrix. Consequently, a blend with enhanced mechanical performance, higher thermal stability, and a higher melt flow index (MFI) is obtained when compared to the blend prepared using unmodified particles. The similarity of the MFI of cork-g-PMMA/PMMA to that of PMMA suggests good printability. Indeed, a three-dimensional (3D) printed specimen is obtained confirming that grafting using ATRP is a promising route for the preparation of high quality 3D printed products. Full article
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17 pages, 6204 KiB  
Article
Development of a Gene Delivery System of Oligonucleotides for Fibroses by Targeting Cell-Surface Vimentin-Expressing Cells with N-Acetylglucosamine-Bearing Polymer-Conjugated Polyethyleneimine
by Inu Song and Hirohiko Ise
Polymers 2020, 12(7), 1508; https://doi.org/10.3390/polym12071508 - 7 Jul 2020
Cited by 7 | Viewed by 3381
Abstract
Targeting myofibroblasts and activated stellate cells in lesion sites of fibrotic tissues is an important approach to treat fibroses. Herein, we focused on targeting the cytoskeletal proteins vimentin, which are reportedly highly expressed on the surface of these cells and have N-acetylglucosamine (GlcNAc)-binding [...] Read more.
Targeting myofibroblasts and activated stellate cells in lesion sites of fibrotic tissues is an important approach to treat fibroses. Herein, we focused on targeting the cytoskeletal proteins vimentin, which are reportedly highly expressed on the surface of these cells and have N-acetylglucosamine (GlcNAc)-binding activity. A GlcNAc-bearing polymer synthesized via radical polymerization with a reversible addition-fragmentation chain transfer reagent has been previously found to interact with cell-surface vimentin-expressing cells. We designed a GlcNAc-bearing polymer-conjugated polyethyleneimine (PEI), as the gene carrier to target cell-surface vimentin-expressing cells and specifically deliver nuclear factor-κB decoy oligonucleotides (ODNs) and heat shock protein 47 (HSP47)-small interfering RNA (siRNA) to normal human dermal fibroblasts (NHDFs) that express cell-surface vimentin. The results showed that the expression of tumor necrosis factor-α in lipopolysaccharide-stimulated NHDFs and HSP47 in transforming growth factor-β1-stimulated NHDFs was suppressed by cellular uptake of the GlcNAc-bearing polymer-conjugated PEI/nuclear factor (NF)-κB decoy ODNs and HSP47-siRNA complexes through cell-surface vimentin, respectively. These findings suggest that the effective and specific delivery of ODNs and siRNA for cell-surface vimentin-expressing cells such as myofibroblasts and activated stellate cells can be achieved using GlcNAc-bearing polymer-conjugated PEI. This therapeutic approach could prove advantageous to prevent the promotion of various fibroses. Full article
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18 pages, 3431 KiB  
Article
Biofunctional Polymer Coated Au Nanoparticles Prepared via RAFT-Assisted Encapsulating Emulsion Polymerization and Click Chemistry
by Sónia O. Pereira, Tito Trindade and Ana Barros-Timmons
Polymers 2020, 12(7), 1442; https://doi.org/10.3390/polym12071442 - 27 Jun 2020
Cited by 3 | Viewed by 3075
Abstract
The use of reversible addition-fragmentation chain transfer (RAFT)-assisted encapsulating emulsion polymerization (REEP) has been explored to prepare diverse types of colloidal stable core–shell nanostructures. A major field of application of such nanoparticles is in emergent nanomedicines, which require effective biofunctionalization strategies, in which [...] Read more.
The use of reversible addition-fragmentation chain transfer (RAFT)-assisted encapsulating emulsion polymerization (REEP) has been explored to prepare diverse types of colloidal stable core–shell nanostructures. A major field of application of such nanoparticles is in emergent nanomedicines, which require effective biofunctionalization strategies, in which their response to bioanalytes needs to be firstly assessed. Herein, functional core–shell nanostructures were prepared via REEP and click chemistry. Thus, following the REEP strategy, colloidal gold nanoparticles (Au NPs, d = 15 nm) were coated with a poly(ethylene glycol) methyl ether acrylate (PEGA) macroRAFT agent containing an azide (N3) group to afford N3–macroRAFT@Au NPs. Then, chain extension was carried out from the NPs surface via REEP, at 44 °C under monomer-starved conditions, to yield N3–copolymer@Au NPs–core–shell type structures. Biotin was anchored to N3–copolymer@Au NPs via click chemistry using an alkynated biotin to yield biofunctionalized Au nanostructures. The response of the ensuing biotin–copolymer@Au NPs to avidin was followed by visible spectroscopy, and the copolymer–biotin–avidin interaction was further studied using the Langmuir–Blodgett technique. This research demonstrates that REEP is a promising strategy to prepare robust functional core–shell plasmonic nanostructures for bioapplications. Although the presence of azide moieties requires the use of low polymerization temperature, the overall strategy allows the preparation of tailor-made plasmonic nanostructures for applications of biosensors based on responsive polymer shells, such as pH, temperature, and photoluminescence quenching. Moreover, the interaction of biotin with avidin proved to be time dependent. Full article
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23 pages, 6201 KiB  
Article
Design of Waterborne Asymmetric Block Copolymers as Thermoresponsive Materials
by Gordana Siljanovska Petreska, Christof van Sluijs, Clemens Auschra and Maria Paulis
Polymers 2020, 12(6), 1253; https://doi.org/10.3390/polym12061253 - 30 May 2020
Viewed by 3027
Abstract
AB diblock waterborne copolymers made of styrene (St) and 2-ethylhexyl acrylate (2EHA) were synthesized by means of two-step reversible addition fragmentation chain transfer (RAFT) (mini)emulsion polymerization. Monofunctional asymmetric RAFT agent was used to initiate the polymerization. The hard polystyrene “A” block was synthesized [...] Read more.
AB diblock waterborne copolymers made of styrene (St) and 2-ethylhexyl acrylate (2EHA) were synthesized by means of two-step reversible addition fragmentation chain transfer (RAFT) (mini)emulsion polymerization. Monofunctional asymmetric RAFT agent was used to initiate the polymerization. The hard polystyrene “A” block was synthesized via miniemulsion polymerization followed by 2EHA pre-emulsion feeding to form the soft “B” block. Polymerization kinetics and the evolution of the molecular weight distribution were followed during synthesis of both initial and final block copolymers. DSC measurements of the block copolymers revealed the existence of two glass transition temperatures (Tgs) and thus the occurrence of two-phase systems. Microscopic techniques (atomic force microscopy (AFM) and transmission electron microscopy (TEM)) were used to study the phase separation within the particles in the latex form, after film formation at room temperature cast directly from the latex and after different post-treatments well above the Tg of the hard-polystyrene domains, when complete particle coalescence had occurred. The morphological differences observed after different annealing temperatures were correlated with the mechanical properties analyzed by DMTA measurements. Finally, the differences found in the mechanical properties of the block copolymers annealed at different temperatures were correlated to their heat seal application results. Full article
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20 pages, 3215 KiB  
Article
Synthesis and Self-Assembly of Poly(N-Vinylcaprolactam)-b-Poly(ε-Caprolactone) Block Copolymers via the Combination of RAFT/MADIX and Ring-Opening Polymerizations
by Rodolfo M. Moraes, Layde T. Carvalho, Gizelda M. Alves, Simone F. Medeiros, Elodie Bourgeat-Lami and Amilton M. Santos
Polymers 2020, 12(6), 1252; https://doi.org/10.3390/polym12061252 - 30 May 2020
Cited by 18 | Viewed by 3923
Abstract
Well-defined amphiphilic, biocompatible and partially biodegradable, thermo-responsive poly(N-vinylcaprolactam)-b-poly(ε-caprolactone) (PNVCL-b-PCL) block copolymers were synthesized by combining reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerizations (ROP). Poly(N-vinylcaprolactam) containing xanthate and hydroxyl end groups (X–PNVCL–OH) was first synthesized [...] Read more.
Well-defined amphiphilic, biocompatible and partially biodegradable, thermo-responsive poly(N-vinylcaprolactam)-b-poly(ε-caprolactone) (PNVCL-b-PCL) block copolymers were synthesized by combining reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerizations (ROP). Poly(N-vinylcaprolactam) containing xanthate and hydroxyl end groups (X–PNVCL–OH) was first synthesized by RAFT/macromolecular design by the interchange of xanthates (RAFT/MADIX) polymerization of NVCL mediated by a chain transfer agent containing a hydroxyl function. The xanthate-end group was then removed from PNVCL by a radical-induced process. Finally, the hydroxyl end-capped PNVCL homopolymer was used as a macroinitiator in the ROP of ε-caprolactone (ε-CL) to obtain PNVCL-b-PCL block copolymers. These (co)polymers were characterized by Size Exclusion Chromatography (SEC), Fourier-Transform Infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance spectroscopy (1H NMR), UV–vis and Differential Scanning Calorimetry (DSC) measurements. The critical micelle concentration (CMC) of the block copolymers in aqueous solution measured by the fluorescence probe technique decreased with increasing the length of the hydrophobic block. However, dynamic light scattering (DLS) demonstrated that the size of the micelles increased with increasing the proportion of hydrophobic segments. The morphology observed by cryo-TEM demonstrated that the micelles have a pointed-oval-shape. UV–vis and DLS analyses showed that these block copolymers have a temperature-responsive behavior with a lower critical solution temperature (LCST) that could be tuned by varying the block copolymer composition. Full article
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13 pages, 8836 KiB  
Article
Flame Retardant Submicron Particles via Surfactant-Free RAFT Emulsion Polymerization of Styrene Derivatives Containing Phosphorous
by Taeyoon Kim, Joo-Hyun Song, Jong-Ho Back, Bongkuk Seo, Choong-Sun Lim, Hyun-Jong Paik and Wonjoo Lee
Polymers 2020, 12(6), 1244; https://doi.org/10.3390/polym12061244 - 29 May 2020
Cited by 4 | Viewed by 2741
Abstract
The reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of diethyl-(4-vinylbenzyl) phosphate (DEVBP) was performed using PEG-TTC as a macro RAFT agent. PEG-TTC (MW 2000, 4000) was synthesized by the esterification of poly (ethylene glycol) methyl ether with a carboxylic-terminated RAFT agent, composed [...] Read more.
The reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of diethyl-(4-vinylbenzyl) phosphate (DEVBP) was performed using PEG-TTC as a macro RAFT agent. PEG-TTC (MW 2000, 4000) was synthesized by the esterification of poly (ethylene glycol) methyl ether with a carboxylic-terminated RAFT agent, composed a hydrophilic poly (ethylene glycol) (PEG) block and a hydrophobic dodecyl chain. The RAFT emulsion polymerization of DEVBP was well–controlled with a narrow molecular size distribution. Dynamic light scattering and confocal laser scanning microscopy were used to examine the PEG-b-PDVBP submicron particles, and the length of the PEG chain (hydrophilic block) was found to affect the particle size distribution and molecular weight distribution. The submicron particle size increased with increasing degree of polymerization (35, 65, and 130), and precipitation was observed at a high degree of polymerization (DP) using low molecular weight PEG-TTC (DP 130, A3). The flame retardant properties of the PEG-b-PDVBP were evaluated by thermogravimetric analysis (TGA) and micro cone calorimeter (MCC). In the combustion process, the residue of PEG-b-PDEVBP were above 500 °C was observed (A1 ~ B3, 27 ~ 38%), and flame retardant effect of PEG-b-PDEVBP submicron particles/PVA composite were confirmed by increasing range of temperature and decreasing total heat release with increasing contents of PEG-b-PDEVBP. The PEG-b-PDEVBP submicron particles can provide flame retardant properties to aqueous, dispersion and emulsion formed organic/polymer products. Full article
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11 pages, 1963 KiB  
Article
A Sacrificial PLA Block Mediated Route to Injectable and Degradable PNIPAAm-Based Hydrogels
by Vernon Tebong Mbah, Vincent Pertici, Céline Lacroix, Bernard Verrier, Pierluigi Stipa, Didier Gigmes and Thomas Trimaille
Polymers 2020, 12(4), 925; https://doi.org/10.3390/polym12040925 - 16 Apr 2020
Cited by 11 | Viewed by 4100
Abstract
Thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-based injectable hydrogels represent highly attractive materials in tissue engineering and drug/vaccine delivery but face the problem of long-term bioaccumulation due to non-degradability. In this context, we developed an amphiphilic poly(D,L-lactide)-b-poly(NIPAAm-co-polyethylene glycol methacrylate) (PLA-b-P(NIPAAm-co-PEGMA)) copolymer architecture, through a combination of ring-opening [...] Read more.
Thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-based injectable hydrogels represent highly attractive materials in tissue engineering and drug/vaccine delivery but face the problem of long-term bioaccumulation due to non-degradability. In this context, we developed an amphiphilic poly(D,L-lactide)-b-poly(NIPAAm-co-polyethylene glycol methacrylate) (PLA-b-P(NIPAAm-co-PEGMA)) copolymer architecture, through a combination of ring-opening and nitroxide-mediated polymerizations, undergoing gelation in aqueous solution near 30 °C. Complete hydrogel mass loss was observed under physiological conditions after few days upon PLA hydrolysis. This was due to the inability of the resulting P(NIPAAm-co-PEGMA) segment, that contains sufficiently high PEG content, to gel. The copolymer was shown to be non-toxic on dendritic cells. These results thus provide a new way to engineer safe PNIPAAm-based injectable hydrogels with PNIPAAm-reduced content and a degradable feature. Full article
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17 pages, 2706 KiB  
Article
Fluoroalkyl Pentacarbonylmanganese(I) Complexes as Initiators for the Radical (co)Polymerization of Fluoromonomers
by Roberto Morales-Cerrada, Vincent Ladmiral, Florence Gayet, Christophe Fliedel, Rinaldo Poli and Bruno Améduri
Polymers 2020, 12(2), 384; https://doi.org/10.3390/polym12020384 - 8 Feb 2020
Cited by 10 | Viewed by 3797
Abstract
The use of [Mn(RF)(CO)5] (RF = CF3, CHF2, CH2CF3, COCF2CH3) to initiate the radical polymerization of vinylidene fluoride (F2C=CH2, VDF) and the radical [...] Read more.
The use of [Mn(RF)(CO)5] (RF = CF3, CHF2, CH2CF3, COCF2CH3) to initiate the radical polymerization of vinylidene fluoride (F2C=CH2, VDF) and the radical alternating copolymerization of vinyl acetate (CH2=CHOOCCH3, VAc) with tert-butyl 2-(trifluoromethyl)acrylate (MAF-TBE) by generating primary RF radicals is presented. Three different initiating methods with [Mn(CF3)(CO)5] (thermal at ca. 100 °C, visible light and UV irradiations) are described and compared. Fair (60%) to satisfactory (74%) polyvinylidene fluoride (PVDF) yields were obtained from the visible light and UV activations, respectively. Molar masses of PVDF reaching 53,000 g·mol−1 were produced from the visible light initiation after 4 h. However, the use of [Mn(CHF2)(CO)5] and [Mn(CH2CF3)(CO)5] as radical initiators produced PVDF in a very low yield (0 to 7%) by both thermal and photochemical initiations, while [Mn(COCF2CH3)(CO)5] led to the formation of PVDF in a moderate yield (7% to 23%). Nevertheless, complexes [Mn(CH2CF3)(CO)5] and [Mn(COCHF2)(CO)5] efficiently initiated the alternating VAc/MAF-TBE copolymerization. All synthesized polymers were characterized by 1H and 19F NMR spectroscopy, which proves the formation of the expected PVDF or poly(VAc-alt-MAF-TBE) and showing the chaining defects and the end-groups in the case of PVDF. The kinetics of VDF homopolymerization showed a linear ln[M]0/[M] versus time relationship, but a decrease of molar masses vs. VDF conversion was noted in all cases, which shows the absence of control. These PVDFs were rather thermally stable in air (up to 410 °C), especially for those having the highest molar masses. The melting points ranged from 164 to 175 °C while the degree of crystallinity varied from 44% to 53%. Full article
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Review

Jump to: Research

16 pages, 3569 KiB  
Review
New Variants of Nitroxide Mediated Polymerization
by Gérard Audran, Elena G. Bagryanskaya, Sylvain R. A. Marque and Pavel Postnikov
Polymers 2020, 12(7), 1481; https://doi.org/10.3390/polym12071481 - 2 Jul 2020
Cited by 34 | Viewed by 5099
Abstract
Nitroxide-mediated polymerization is now a mature technique, at 35 years of age. During this time, several variants have been developed: electron spin capture polymerization (ESCP), photoNMP (NMP2), chemically initiated NMP (CI-NMP), spin label NMP (SL-NMP), and plasmon-initiated NMP (PI-NMP). This mini-review is devoted [...] Read more.
Nitroxide-mediated polymerization is now a mature technique, at 35 years of age. During this time, several variants have been developed: electron spin capture polymerization (ESCP), photoNMP (NMP2), chemically initiated NMP (CI-NMP), spin label NMP (SL-NMP), and plasmon-initiated NMP (PI-NMP). This mini-review is devoted to the features and applications of these variants. Full article
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24 pages, 4602 KiB  
Review
Glycopolymer Brushes by Reversible Deactivation Radical Polymerization: Preparation, Applications, and Future Challenges
by Jessica P. M. Ribeiro, Patrícia V. Mendonça, Jorge F. J. Coelho, Krzysztof Matyjaszewski and Arménio C. Serra
Polymers 2020, 12(6), 1268; https://doi.org/10.3390/polym12061268 - 1 Jun 2020
Cited by 8 | Viewed by 5030
Abstract
The cellular surface contains specific proteins, also known as lectins, that are carbohydrates receptors involved in different biological events, such as cell–cell adhesion, cell recognition and cell differentiation. The synthesis of well-defined polymers containing carbohydrate units, known as glycopolymers, by reversible deactivation radical [...] Read more.
The cellular surface contains specific proteins, also known as lectins, that are carbohydrates receptors involved in different biological events, such as cell–cell adhesion, cell recognition and cell differentiation. The synthesis of well-defined polymers containing carbohydrate units, known as glycopolymers, by reversible deactivation radical polymerization (RDRP) methods allows the development of tailor-made materials with high affinity for lectins because of their multivalent interaction. These polymers are promising candidates for the biomedical field, namely as novel diagnostic disease markers, biosensors, or carriers for tumor-targeted therapy. Although linear glycopolymers are extensively studied for lectin recognition, branched glycopolymeric structures, such as polymer brushes can establish stronger interactions with lectins. This specific glycopolymer topology can be synthesized in a bottlebrush form or grafted to/from surfaces by using RDRP methods, allowing a precise control over molecular weight, grafting density, and brush thickness. Here, the preparation and application of glycopolymer brushes is critically discussed and future research directions on this topic are suggested. Full article
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