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Bruno Ameduri - One of the best experts on this subject based on the ideXlab platform.
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cobalt mediated Radical Copolymerization of vinylidene fluoride and 2 3 3 3 trifluoroprop 1 ene
Polymers, 2021Co-Authors: Panagiotis G Falireas, Bruno AmeduriAbstract:New copolymers based on vinylidene fluoride (VDF) and 2,3,3,3-tetrafluoroprop-1-ene (1234yf) were synthesized by organometallic-mediated Radical Copolymerization (OMRcP) using the combination of bis(tert-butylcyclohexyl) peroxydicarbonate initiator and bis(acetylacetonato)cobalt(II), (Co(acac)2) as a controlling agent. Kinetics studies of the Copolymerization of the fluoroalkenes copolymers were monitored by GPC and 19F NMR with molar masses up to 12,200 g/mol and dispersities (Đ) ranging from 1.33 to 1.47. Such an OMRcP behaves as a controlled Copolymerization, evidenced by the molar mass of the resulting copolymer-monomer conversion linear relationship. The reactivity ratios, ri, of both comonomers were determined by using the Fineman-Ross and Kelen-Tudos fitting model leading to rVDF = 0.384 ± 0.013 and r1234yf = 2.147 ± 0.129 at 60 °C, showing that a lower reactivity of VDF integrated in the copolymer to a greater extent leads to the production of gradient or pseudo-diblock copolymers. In addition, the Q (0.03) and e (0.06 and 0.94) parameters were assessed, as well as the dyad statistic distributions and mean square sequence lengths of PVDF and P1234yf.
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molecular aggregation structure and surface properties of biomimetic catechol bearing poly 2 perfluorooctyl ethyl acrylate and its application to superamphiphobic coatings
ACS Omega, 2020Co-Authors: Bruno Ameduri, Atsushi TakaharaAbstract:The molecular aggregation structure and surface properties of a catechol-bearing fluoropolymer, P(FAC8-co-DOPAm), which was synthesized by conventional Radical Copolymerization of 2-(perfluorooctyl...
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alternating Radical Copolymerization of vinyl acetate and tert butyl 2 trifluoromethacrylate
European Polymer Journal, 2018Co-Authors: Vincent Ladmiral, Sanjib Banerjee, Cedric Totee, Bruno AmeduriAbstract:Abstract Alternating conventional Radical Copolymerization of tert-butyl-2-trifluoromethacrylate (a non-homopolymerizable fluoromonomer under Radical conditions) with vinyl acetate, initiated by 2,2′-azo-bis(4-methoxy-2,4-dimethyl valeronitrile) at 40 °C is presented. The study of the kinetics of the Copolymerization using various [VAc]0/[MAF-TBE]0 feeds showed that an equimolar feed of comonomers led to the highest apparent Copolymerization rate (kapp = 4 × 10−4 s−1). The resulting copolymers had a nearly perfect alternating structure over a very wide range of comonomer feed compositions (fMAF-TBE = 0.05–0.95) until complete consumption of one of the monomers. The reactivity ratios were measured to be: rMAF-TBE = 0 and rVAc = 0.014 at 40 °C and the Alfrey and Price parameters for MAF-TBE were calculated (QMAF-TBE = 1.18 and eMAF-TBE = 1.84).
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Poly(fluoroacrylate)s with tunable surface hydrophobicity via Radical Copolymerization of 2,2,2-trifluoroethyl α-fluoroacrylate and 2-(trifluoromethyl)acrylic acid
Polymer Chemistry, 2017Co-Authors: Bruno Ameduri, Sanjib Banerjee, Vincent Ladmiral, Bhausaheb Tawade, Lionel Dupuy, Michael MacdonaldAbstract:The synthesis of poly(fluoroacrylate)s with tunable wettability and improved adhesion for potential application as functional coatings was achieved via Radical Copolymerization of 2,2,2-trifluoroethyl α-fluoroacrylate (FATRIFE) with 2-(trifluoromethyl)acrylic acid (MAF), an adhesion-promoting monomer. These Copolymerizations, initiated by tert-butyl peroxypivalate at varying comonomer feed ([FATRIFE]0/ [MAF]0) ratios led to a series of poly(FATRIFE-co-MAF) copolymers with different molar compositions in fair to good conversions (32–87%) depending on the MAF feed content. The microstructures of the synthesized poly(FATRIFE-co-MAF) copolymers were determined by 19F NMR spectroscopy. Even at MAF feed contents higher than 50%, MAF incorporation into the copolymers was lower than 50%, since MAF does not undergo any homopolymerization under Radical polymerization conditions. The reactivity ratios of the (FATRIFE; MAF) monomer pair were also determined (rFATRIFE = 1.65 ± 0.07 and rMAF = 0 at 56 °C) evidencing the formation of statistical copolymers. Initiation involving a highly branched perfluorinated Radical that released a •CF3 Radical enabled the demonstration of the regioselective attack of the latter Radical onto the CH2 of FATRIFE. The resulting poly(FATRIFE-co-MAF) copolymers exhibited various glass transition temperatures (Tgs) depending on their compositions. Tg values increased with increasing MAF contents in the copolymer. In addition, their thermal stability (the temperature for 10% weight loss in air, Td10%) increased with increasing FATRIFE content in the copolymer and reached 348 °C (for that containing 93 mol% FATRIFE). Finally, a high copolymer MAF content led to both a good adhesion onto metal substrates and to improved hydrophilicity, as revealed by the decrease of the water contact angle from 107° (for a reference PFATRIFE homopolymer) to 81° (for a copolymer containing 42 mol% MAF).
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Radical Copolymerization of Vinylidene Fluoride (VDF) with Oligo(hexafluoropropylene oxide) Perfluorovinyl Ether Macromonomer To Obtain PVDF‑g‑oligo(HFPO) Graft Copolymers
2015Co-Authors: Chadron M. Friesen, Bruno AmeduriAbstract:The synthesis of PVDF-g-oligo(HFPO) graft copolymers, where VDF and HFPO stand for vinylidene fluoride and hexafluoropropylene oxide, respectively, is presented. First, an oligo(HFPO)–OCFCF2 macromonomer was prepared from two methods starting from oligo(HFPO) acyl fluoride in 34 to 54% yield. Then, the Radical Copolymerization of VDF with that comonomer, initiated by tert-butyl peroxypivalate (TBPPi) or perfluoro-3-ethyl-2,4-dimethyl-3-pentyl persistent Radical (PPFR) was studied under various conditions. The resulting PVDF-g-oligo(HFPO) graft copolymers were produced in good isolated yields (74 to 89%). The molar percentages and molecular weights of the graft copolymers were assessed by 19F and 1H NMR spectroscopy. Molar percentages of VDF and oligo(HFPO)–OCFCF2 comonomers reached up to 99% and 11%, respectively, while the molecular weights ranged from 25 000 to 77 000 g/mol. Their thermal properties were also studied and showed: (1) satisfactory thermostability (Td) in the 410 to 494 °C range under air and (2) melting temperature (Tm) between 138 to 159 °C, while (3) the glass transition (Tg) ranged from −79 to −54 °C
Masami Kamigaito - One of the best experts on this subject based on the ideXlab platform.
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controlled Radical Copolymerization of cinnamic derivatives as renewable vinyl monomers with both acrylic and styrenic substituents reactivity regioselectivity properties and functions
Biomacromolecules, 2019Co-Authors: Yuya Terao, Kotaro Satoh, Masami KamigaitoAbstract:A series of cinnamic monomers, which can be derived from naturally occurring phenylpropanoids, were Radically copolymerized with vinyl monomers such as methyl acrylate (MA) and styrene (St). Although the monomer reactivity ratios were close to zero for all the cinnamic monomers, such as methyl cinnamate (CAMe), cinnamic acid (CA), N-isopropyl cinnamide (CNIPAm), cinnamaldehyde (CAld), and cinnamonitrile (CN), they were incorporated into the copolymers and significantly increased the glass transition temperatures despite the relatively low incorporation rates of up to 40 mol % due to their rigid 1,2-disubstituted structures. The regioselectivity of the Radical Copolymerization of CAMe was evaluated on the basis of the results of ruthenium-catalyzed atom transfer Radical additions as model reactions. The obtained products suggest that the Radicals of MA and St predominantly attack the vinyl carbon of the carbonyl side of CAMe and that the propagation of CAMe mainly occurs via the styrenic Radical. The ruthe...
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Controlled Radical Copolymerization of Cinnamic Derivatives as Renewable Vinyl Monomers with Both Acrylic and Styrenic Substituents: Reactivity, Regioselectivity, Properties, and Functions
2018Co-Authors: Yuya Terao, Kotaro Satoh, Masami KamigaitoAbstract:A series of cinnamic monomers, which can be derived from naturally occurring phenylpropanoids, were Radically copolymerized with vinyl monomers such as methyl acrylate (MA) and styrene (St). Although the monomer reactivity ratios were close to zero for all the cinnamic monomers, such as methyl cinnamate (CAMe), cinnamic acid (CA), N-isopropyl cinnamide (CNIPAm), cinnamaldehyde (CAld), and cinnamonitrile (CN), they were incorporated into the copolymers and significantly increased the glass transition temperatures despite the relatively low incorporation rates of up to 40 mol % due to their rigid 1,2-disubstituted structures. The regioselectivity of the Radical Copolymerization of CAMe was evaluated on the basis of the results of ruthenium-catalyzed atom transfer Radical additions as model reactions. The obtained products suggest that the Radicals of MA and St predominantly attack the vinyl carbon of the carbonyl side of CAMe and that the propagation of CAMe mainly occurs via the styrenic Radical. The ruthenium-catalyzed living Radical polymerization, nitroxide-mediated polymerization (NMP), and reversible addition–fragmentation chain transfer (RAFT) polymerization provided the copolymers with controlled molecular weights, narrow molecular weight distributions, and controlled comonomer compositions. The copolymers of N-isopropylacrylamide (NIPAM) and CNIPAm prepared via RAFT Copolymerization showed thermoresponsivity with a lower critical solution temperature (LCST) that could be tuned by altering the comonomer incorporation and a higher LCST than the copolymers of NIPAM and St, which possessed similar molecular weights and similar NIPAM contents, due to the additional N-isopropylamide groups in the CNIPAm units compared to the St units
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main chain and side chain sequence regulated vinyl copolymers by iterative atom transfer Radical additions and 1 1 or 2 1 alternating Radical Copolymerization
Journal of the American Chemical Society, 2016Co-Authors: Takamasa Soejima, Kotaro Satoh, Masami KamigaitoAbstract:Main- and side-chain sequence-regulated vinyl copolymers were prepared by a combination of iterative atom transfer Radical additions (ATRAs) of vinyl monomers for side-chain control and 1:1 or 2:1 alternating Radical Copolymerization of the obtained side-chain sequenced “oligomonomers” and vinyl comonomers for main-chain control. A complete set of sequence-regulated trimeric vinyl oligomers of styrene (S) and/or methyl acrylate (A) were first synthesized via iterative ATRAs of these monomers to a halide of monomeric S or A unit (X–S or X–A) under optimized conditions with appropriate ruthenium or copper catalysts, which were selected depending on the monomers and halides. The obtained halogen-capped oligomers were then converted into a series of maleimide (M)-ended oligomonomers with different monomer compositions and sequences (M–SSS, M–ASS, M–SAS, M–AAS, M–SSA, M–ASA, M–SAA, M–AAA) by a substitution reaction of the halide with furan-protected maleimide anion followed by deprotection of the furan units. ...
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Sequence-regulated vinyl copolymers with acid and base monomer units via atom transfer Radical addition and alternating Radical Copolymerization
Polymer Chemistry, 2016Co-Authors: Takamasa Soejima, Kotaro Satoh, Masami KamigaitoAbstract:Main- and side-chain sequence-regulated vinyl copolymers with acid and base monomer units were prepared using atom transfer Radical addition (ATRA) and alternating Radical Copolymerization. A series of maleimide-ended sequence-regulated “oligomonomers” were prepared by ATRA of t-butyl acrylate (tBA: Ap) (i.e., a protected acrylic acid (A)) or an amine-functionalized acrylate, (2-(dimethylamino)ethyl acrylate (DMAEA: B)), and styrene (S) followed by an SN2 reaction of furan-protected maleimide (M) anion and its deprotection. The obtained maleimide-ended oligomonomers (M–ApS, M–SAp, M–BS, M–SB) were copolymerized with S in alternating reversible addition–fragmentation chain transfer (RAFT) Copolymerizations, resulting in main- and side-chain sequence-regulated copolymers with controlled molecular weights. After deprotection of the t-butyl group, the acid and base interactions between the copolymers were evaluated by dynamic light scattering (DLS) of the polymer solutions. All the mixtures resulted in submicron particles, and the size depended on the sequence of acid monomers in the side chains. The effects of the functionalized monomer sequences on the thermal properties were also examined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
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monomer sequence regulation in main and side chains of vinyl copolymers synthesis of vinyl oligomonomers via sequential atom transfer Radical addition and their alternating Radical Copolymerization
ACS Macro Letters, 2015Co-Authors: Takamasa Soejima, Kotaro Satoh, Masami KamigaitoAbstract:We propose a novel strategy of monomer sequence regulation in main and side chains of vinyl copolymers using sequential atom transfer Radical addition (ATRA) for maleimide-ended sequence-regulated vinyl “oligomonomers” and their alternating Radical Copolymerization with styrene. To establish this strategy, a series of sequence-regulated vinyl oligomers were prepared by the ATRA of styrene (S) or methyl acrylate (A) to a halide-possessing A or S unit (methyl α-bromopropionate or 1-phenylethylhalide). The obtained halide-ended sequence-regulated vinyl oligomers were converted into maleimide-ended oligomonomers by SN2 reaction with the potassium salt of furan-protected maleimide (M) followed by deprotection. The maleimide-ended oligomonomers were then Radically copolymerized with styrene in an alternating fashion to result in sequence-regulated vinyl copolymers consisting of a controlled monomer sequence (SA, AS, AA, and SS) in the side chain and an alternating sequence (MS) in the main chain. The solubility...
Akikazu Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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Sequence-Controlled Radical Copolymerization of N‑Substituted Maleimides with Olefins and Polyisobutene Macromonomers To Fabricate Thermally Stable and Transparent Maleimide Copolymers with Tunable Glass Transition Temperatures and Viscoelastic Prope
2016Co-Authors: Miki Hisano, Kyota Takeda, Tsutomu Takashima, Zhengzhe Jin, Akira Shiibashi, Akikazu MatsumotoAbstract:Thermally stable and transparent polymers were synthesized by the sequence-controlled Radical Copolymerization of N-substituted maleimides (RMIs) with various olefins as well as polyisobutene (PIB) macromonomers. The Copolymerization behavior significantly depended on the olefin structures, leading to the formation of AB-alternating and AAB-periodic (2:1 sequence-controlled) copolymers. The sequence-controlled Radical Copolymerization mechanism was discussed based on the monomer reactivity ratios, which were determined using terminal and penultimate unit models for the Copolymerization systems investigated in this study as well as in the literature. The olefin comonomers were classified into several groups according to the Copolymerization fashions under the terminal and penultimate unit controls and their conjugated structure and the steric bulkiness of the substituents. The copolymers exhibited excellent thermal properties; the onset temperatures of the resulting copolymers were higher than 300 °C, and the glass transition temperature (Tg) values varied over the temperature range of −68 to 210 °C, depending on the structure of the N- and α-substituents of the comonomer repeating units. The introduction of sterically hindered substituents increased the Tg values, while the introduction of the PIB segments as the side chain of the copolymers resulted in a significant decrease in the Tg value and unique fluidity. The optical and viscoelastic properties of the high-Tg copolymers were investigated
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sequence controlled Radical Copolymerization of n substituted maleimides with olefins and polyisobutene macromonomers to fabricate thermally stable and transparent maleimide copolymers with tunable glass transition temperatures and viscoelastic prope
Macromolecules, 2013Co-Authors: Miki Hisano, Kyota Takeda, Tsutomu Takashima, Zhengzhe Jin, Akira Shiibashi, Akikazu MatsumotoAbstract:Thermally stable and transparent polymers were synthesized by the sequence-controlled Radical Copolymerization of N-substituted maleimides (RMIs) with various olefins as well as polyisobutene (PIB) macromonomers. The Copolymerization behavior significantly depended on the olefin structures, leading to the formation of AB-alternating and AAB-periodic (2:1 sequence-controlled) copolymers. The sequence-controlled Radical Copolymerization mechanism was discussed based on the monomer reactivity ratios, which were determined using terminal and penultimate unit models for the Copolymerization systems investigated in this study as well as in the literature. The olefin comonomers were classified into several groups according to the Copolymerization fashions under the terminal and penultimate unit controls and their conjugated structure and the steric bulkiness of the substituents. The copolymers exhibited excellent thermal properties; the onset temperatures of the resulting copolymers were higher than 300 °C, and ...
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sequence controlled Radical polymerization of n substituted maleimides with 1 methylenebenzocycloalkanes and the characterization of the obtained copolymers with excellent thermal resistance and transparency
Macromolecules, 2013Co-Authors: Miki Hisano, Kyota Takeda, Tsutomu Takashima, Zhengzhe Jin, Akira Shiibashi, Akikazu MatsumotoAbstract:The Radical Copolymerization of N-methyl, ethyl, n-butyl, and 2-ethylhexylmaleimides (RMIs) with 1-methylenebenzocycloalkanes (BCms) was carried out to fabricate thermally stable and transparent polymer materials. The Copolymerization reactivity of BCms significantly depended on the carbon number of the ring structure of BCms. The analyses of the comonomer–copolymer composition curves and theoretical calculations results revealed that the sequence-controlled Copolymerization of RMIs with BCms occurred in alternating and 2:1 fashions according to the BCms reactivity, which depends on the coplanarity of the exomethylene moiety and the benzene ring. The alternating and high-molecular-weight copolymers of BCms and RMIs exhibited excellent thermal and optical properties. We have demonstrated that the Radical Copolymerization of RMIs is useful not only as the method for high-performance transparent polymer production but also as the tool for the fundamental research of Radical polymerization mechanism.
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thermally stable polysulfones obtained by regiospecific Radical Copolymerization of various acyclic and cyclic 1 3 diene monomers with sulfur dioxide and subsequent hydrogenation
Macromolecules, 2011Co-Authors: Naruki Tanaka, Eriko Sato, Akikazu MatsumotoAbstract:We synthesized the thermally stable alternating copolymers from various acyclic and cyclic alkyl-substituted 1,3-diene monomers with sulfur dioxide (SO2) as the starting comonomers by Radical Copolymerization and subsequent hydrogenation. It was revealed based on the DFT calculation results using model reactions as well as the thermodynamic analysis of polymerization that some propagation steps were reversible and the highly 1,4-regiospecific sequences of the poly(diene sulfone)s (PDSs) were consequently produced via a free Radical propagation mechanism. The stereochemical structures of the PDSs obtained from cyclic 1,3-diene monomers, such as 1,3-cyclopentadiene and 1,3-cyclohexadiene, were also estimated based on the DFT calculations. Transparent films with a refractive index of 1.53–1.55 were readily obtained by casting the PDS solutions, being confirmed to be amorphous by wide-angle X-ray diffraction measurements. The decomposition of the PDSs started below 150 °C, but hydrogenation produced thermally...
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soluble and thermally stable polysulfones prepared by the regiospecific and alternating Radical Copolymerization of 2 4 hexadiene with sulfur dioxide
Macromolecules, 2010Co-Authors: Tomoaki Kitamura, Naruki Tanaka, Asako Mihashi, Akikazu MatsumotoAbstract:We synthesized the alternating copolymers of 1,3-diene monomers with sulfur dioxide (SO2) as a new class of thermally stable polymers by the Radical Copolymerization process and the subsequent hydrogenation. The Copolymerizations of 2,4-hexadiene (HD), 1,3-butadiene (BD), and isoprene (IP) with SO2 were carried out at −78 to 0 °C in toluene in the presence of tert-butyl hydroperoxide, which acts as one component in the redox initiating system in combination with SO2. The resulting poly(diene-alt-SO2)s were found to consist of highly controlled repeating units, that is, an alternating and 1,4-regiospecific repeating structure. Poly(HD-alt-SO2) was soluble in several organic solvents, such as chloroform, nitromethane, tetrahydrofuran, acetone, and dimethyl sulfoxide. In contrast, poly(IP-alt-SO2) was soluble only in dimethyl sulfoxide, whereas poly(BD-alt-SO2) was insoluble in all of the solvents. The poly(diene-alt-SO2)s readily degraded upon heating because of the expected fast depolymerization. We have d...
Krzysztof Matyjaszewski - One of the best experts on this subject based on the ideXlab platform.
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comprehensive modeling study of nitroxide mediated controlled living Radical Copolymerization of methyl methacrylate with a small amount of styrene
Macromolecules, 2009Co-Authors: Julien Nicolas, Krzysztof Matyjaszewski, Laura Mueller, Charlotte Dire, Bernadette CharleuxAbstract:This article presents a comprehensive kinetic study of the SG1 nitroxide-mediated Copolymerization of methyl methacrylate with a small percentage of styrene using the PREDICI software. The aim of this study was to confirm the results from a previous publication showing that a living polymerization can be achieved for this system. The PREDICI simulations based on the penultimate unit effect model were also able to give a better insight into the complex mechanism of nitroxide-mediated controlled Radical Copolymerization. The model showed the Copolymerization kinetics and the evolution of the number average molar mass, the fraction of living and dead chains, and the concentration of the four types of alkoxyamines and propagating Radicals with monomer conversion. It was applied for different initial percentages of styrene and different initiator concentrations.
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influence of initiation efficiency and polydispersity of primary chains on gelation during atom transfer Radical Copolymerization of monomer and cross linker
Macromolecules, 2009Co-Authors: Haifeng Gao, Krzysztof MatyjaszewskiAbstract:The influence of initiation efficiency and polydispersity of primary chains on the experimental gel points was studied during atom transfer Radical Copolymerization (ATRcP) of monovinyl monomer and...
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improving the structural control of graft copolymers Copolymerization of poly dimethylsiloxane macromonomer with methyl methacrylate using raft polymerization
Macromolecular Rapid Communications, 2001Co-Authors: Hosei Shinoda, Krzysztof MatyjaszewskiAbstract:Reversible addition-fragmentation chain transfer was applied to the Copolymerization of methyl methacrylate and a methacrylate-terminated poly-(dimethylsiloxane) macromonomer (PDMS-MA). The relative reactivity of PDMS-MA (1/rMMA) was higher than in the conventional Radical Copolymerization and similar to that in the atom transfer Radical Copolymerization. The obtained graft copolymers had much lower polydispersities than those obtained in the conventional Radical systems.
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improving the structural control of graft copolymers by combining atrp with the macromonomer method
Macromolecules, 2001Co-Authors: Hosei Shinoda, Peter J Miller, Krzysztof MatyjaszewskiAbstract:The reactivity ratios of methyl methacrylate (MMA) and methacryloyl-terminated poly(dimethylsiloxane) macromonomer (PDMS-MA) were determined in four different systems, using either conventional Radical Copolymerization or atom transfer Radical Copolymerization (ATRP) and using low molecular weight initiators or poly(dimethylsiloxane) macroinitiators. While the relative reactivity of PDMS-MA (1/rMMA) decreased to 0.3−0.4 in the conventional Radical polymerization, the reactivity ratio was higher in ATRP systems (ca. 0.8). The use of macroinitiator in the ATRP system increased 1/rMMA at high concentration and helped regularly incorporate PDMS-MA into the copolymer. However, in the conventional Radical polymerization or redox systems, macro(azo)initiator did not as significantly improve the reactivity ratio of PDMS-MA. Graft copolymers obtained by ATRP (in both solution and semibulk) have much lower polydispersities than obtained in conventional Radical systems.
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gradient copolymers by atom transfer Radical Copolymerization
Journal of Physical Organic Chemistry, 2000Co-Authors: Krzysztof Matyjaszewski, Michael J Ziegler, Stephen V Arehart, Dorota Greszta, Tadeusz PakulaAbstract:Gradient copolymers, in which the instantaneous composition varies continuously along each chain, are discussed in terms of theoretical background, significance and examples from the literature. The specific focus is the use of atom transfer Radical polymerization to synthesize gradient copolymers with various composition profiles. Examples of gradient copolymers using ionic and controlled Radical polymerization techniques are presented. Atom transfer Radical polymerization has been used under both batch and semi-batch conditions to produce gradient copolymers. The physical properties of gradient copolymers and possible future work in the field of gradient copolymers are discussed. Copyright © 2000 John Wiley & Sons, Ltd.
Kotaro Satoh - One of the best experts on this subject based on the ideXlab platform.
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controlled Radical Copolymerization of cinnamic derivatives as renewable vinyl monomers with both acrylic and styrenic substituents reactivity regioselectivity properties and functions
Biomacromolecules, 2019Co-Authors: Yuya Terao, Kotaro Satoh, Masami KamigaitoAbstract:A series of cinnamic monomers, which can be derived from naturally occurring phenylpropanoids, were Radically copolymerized with vinyl monomers such as methyl acrylate (MA) and styrene (St). Although the monomer reactivity ratios were close to zero for all the cinnamic monomers, such as methyl cinnamate (CAMe), cinnamic acid (CA), N-isopropyl cinnamide (CNIPAm), cinnamaldehyde (CAld), and cinnamonitrile (CN), they were incorporated into the copolymers and significantly increased the glass transition temperatures despite the relatively low incorporation rates of up to 40 mol % due to their rigid 1,2-disubstituted structures. The regioselectivity of the Radical Copolymerization of CAMe was evaluated on the basis of the results of ruthenium-catalyzed atom transfer Radical additions as model reactions. The obtained products suggest that the Radicals of MA and St predominantly attack the vinyl carbon of the carbonyl side of CAMe and that the propagation of CAMe mainly occurs via the styrenic Radical. The ruthe...
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Controlled Radical Copolymerization of Cinnamic Derivatives as Renewable Vinyl Monomers with Both Acrylic and Styrenic Substituents: Reactivity, Regioselectivity, Properties, and Functions
2018Co-Authors: Yuya Terao, Kotaro Satoh, Masami KamigaitoAbstract:A series of cinnamic monomers, which can be derived from naturally occurring phenylpropanoids, were Radically copolymerized with vinyl monomers such as methyl acrylate (MA) and styrene (St). Although the monomer reactivity ratios were close to zero for all the cinnamic monomers, such as methyl cinnamate (CAMe), cinnamic acid (CA), N-isopropyl cinnamide (CNIPAm), cinnamaldehyde (CAld), and cinnamonitrile (CN), they were incorporated into the copolymers and significantly increased the glass transition temperatures despite the relatively low incorporation rates of up to 40 mol % due to their rigid 1,2-disubstituted structures. The regioselectivity of the Radical Copolymerization of CAMe was evaluated on the basis of the results of ruthenium-catalyzed atom transfer Radical additions as model reactions. The obtained products suggest that the Radicals of MA and St predominantly attack the vinyl carbon of the carbonyl side of CAMe and that the propagation of CAMe mainly occurs via the styrenic Radical. The ruthenium-catalyzed living Radical polymerization, nitroxide-mediated polymerization (NMP), and reversible addition–fragmentation chain transfer (RAFT) polymerization provided the copolymers with controlled molecular weights, narrow molecular weight distributions, and controlled comonomer compositions. The copolymers of N-isopropylacrylamide (NIPAM) and CNIPAm prepared via RAFT Copolymerization showed thermoresponsivity with a lower critical solution temperature (LCST) that could be tuned by altering the comonomer incorporation and a higher LCST than the copolymers of NIPAM and St, which possessed similar molecular weights and similar NIPAM contents, due to the additional N-isopropylamide groups in the CNIPAm units compared to the St units
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main chain and side chain sequence regulated vinyl copolymers by iterative atom transfer Radical additions and 1 1 or 2 1 alternating Radical Copolymerization
Journal of the American Chemical Society, 2016Co-Authors: Takamasa Soejima, Kotaro Satoh, Masami KamigaitoAbstract:Main- and side-chain sequence-regulated vinyl copolymers were prepared by a combination of iterative atom transfer Radical additions (ATRAs) of vinyl monomers for side-chain control and 1:1 or 2:1 alternating Radical Copolymerization of the obtained side-chain sequenced “oligomonomers” and vinyl comonomers for main-chain control. A complete set of sequence-regulated trimeric vinyl oligomers of styrene (S) and/or methyl acrylate (A) were first synthesized via iterative ATRAs of these monomers to a halide of monomeric S or A unit (X–S or X–A) under optimized conditions with appropriate ruthenium or copper catalysts, which were selected depending on the monomers and halides. The obtained halogen-capped oligomers were then converted into a series of maleimide (M)-ended oligomonomers with different monomer compositions and sequences (M–SSS, M–ASS, M–SAS, M–AAS, M–SSA, M–ASA, M–SAA, M–AAA) by a substitution reaction of the halide with furan-protected maleimide anion followed by deprotection of the furan units. ...
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Sequence-regulated vinyl copolymers with acid and base monomer units via atom transfer Radical addition and alternating Radical Copolymerization
Polymer Chemistry, 2016Co-Authors: Takamasa Soejima, Kotaro Satoh, Masami KamigaitoAbstract:Main- and side-chain sequence-regulated vinyl copolymers with acid and base monomer units were prepared using atom transfer Radical addition (ATRA) and alternating Radical Copolymerization. A series of maleimide-ended sequence-regulated “oligomonomers” were prepared by ATRA of t-butyl acrylate (tBA: Ap) (i.e., a protected acrylic acid (A)) or an amine-functionalized acrylate, (2-(dimethylamino)ethyl acrylate (DMAEA: B)), and styrene (S) followed by an SN2 reaction of furan-protected maleimide (M) anion and its deprotection. The obtained maleimide-ended oligomonomers (M–ApS, M–SAp, M–BS, M–SB) were copolymerized with S in alternating reversible addition–fragmentation chain transfer (RAFT) Copolymerizations, resulting in main- and side-chain sequence-regulated copolymers with controlled molecular weights. After deprotection of the t-butyl group, the acid and base interactions between the copolymers were evaluated by dynamic light scattering (DLS) of the polymer solutions. All the mixtures resulted in submicron particles, and the size depended on the sequence of acid monomers in the side chains. The effects of the functionalized monomer sequences on the thermal properties were also examined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
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monomer sequence regulation in main and side chains of vinyl copolymers synthesis of vinyl oligomonomers via sequential atom transfer Radical addition and their alternating Radical Copolymerization
ACS Macro Letters, 2015Co-Authors: Takamasa Soejima, Kotaro Satoh, Masami KamigaitoAbstract:We propose a novel strategy of monomer sequence regulation in main and side chains of vinyl copolymers using sequential atom transfer Radical addition (ATRA) for maleimide-ended sequence-regulated vinyl “oligomonomers” and their alternating Radical Copolymerization with styrene. To establish this strategy, a series of sequence-regulated vinyl oligomers were prepared by the ATRA of styrene (S) or methyl acrylate (A) to a halide-possessing A or S unit (methyl α-bromopropionate or 1-phenylethylhalide). The obtained halide-ended sequence-regulated vinyl oligomers were converted into maleimide-ended oligomonomers by SN2 reaction with the potassium salt of furan-protected maleimide (M) followed by deprotection. The maleimide-ended oligomonomers were then Radically copolymerized with styrene in an alternating fashion to result in sequence-regulated vinyl copolymers consisting of a controlled monomer sequence (SA, AS, AA, and SS) in the side chain and an alternating sequence (MS) in the main chain. The solubility...
