Experimental Requirements for an Efficient Control of Free‐Radical Polymerizations via the Reversible Addition‐Fragmentation Chain Transfer (RAFT) Process

Favier, Arnaud; Charreyre, Marie‐Thérèse

doi:10.1002/marc.200500839

Cited by 433 publications

(355 citation statements)

References 379 publications

(556 reference statements)

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“…[30][31][32] Alternatively, values for C tr have also been determined based on approximate analytical correlations for the polymer dispersity ( Ð ) profi le. For example, under the stringent model assumptions that conventional radical initiation occurs instantaneously and termination is irrelevant, Muller et al [ 22,23 ] derived a set of analytical expressions for the average polymer properties as function of x. Based on the work of Muller et al, [ 22 , 23 ] Goto and Fukuda [ 25,33 ] proposed various methods to determine C tr .…”

Section: Methods To Determine C Trmentioning

confidence: 99%

“…[ 14,15 ] Similar to the conventional CTAs used in FRP, the classifi cation of R 0 X species is achieved based on a RAFT transfer coeffi cient C tr,0 , defi ned as the ratio of k tr,0 to k p , with the general rule of thumb that low polymer dispersities are obtained for C tr,0 > 10. [ 15,21,22 ] Furthermore, for the reverse transfer and for the macro-RAFT CTA a similar ratio can be defi ned, i.e., respectively, C −tr,0 and C tr . Hence, three transfer coeffi cients are required for a proper description of the degenerative RAFT polymerization process, as summarized in Table 1 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chain Transfer in Degenerative RAFT Polymerization Revisited: A Comparative Study of Literature Methods

Derboven

Steenberge

Reyniers

et al. 2016

Macro Theory & Simulations

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Under the validity of the degenerative transfer mechanism, the activation/deactivation process in reversible addition-fragmentation chain transfer (RAFT) polymerization can be formally quantifi ed by transfer coeffi cients, depending on the chemical structure of the participating radicals and dormant species. In the present work, the different literature methods to experimentally determine these RAFT transfer coeffi cients are reviewed and theoretically re-evaluated. The accuracy of each method is mapped for a broad range of reaction conditions and RAFT transfer reactivities. General guidelines on when which method should be applied are formulated.

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Section: Methods To Determine C Trmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Chain Transfer in Degenerative RAFT Polymerization Revisited: A Comparative Study of Literature Methods

Derboven

Steenberge

Reyniers

et al. 2016

Macro Theory & Simulations

View full text Add to dashboard Cite

show abstract

“…Although previous general reviews have covered both synthetic aspects [43][44][45][46][47][48] and to a lesser extent the applications [49][50][51] of RAFT, no such work has focused on a single important class of polymers from synthesis to applications. This document will cover all vinyl ester monomers which have been polymerized with a RAFT agent.…”

Section: Introductionmentioning

confidence: 99%

RAFT Polymerization of Vinyl Esters: Synthesis and Applications

et al. 2014

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This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT) polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester) building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of the range, many vinyl esters have been considered in order to tune various polymer properties, in particular, solubility in supercritical carbon dioxide (scCO 2 ). A special emphasis is given to novel poly(vinyl alkylate)s with enhanced solubilities in scCO 2 , with applications as reactive stabilizers for dispersion polymerization and macromolecular surfactants for CO 2 media. Other miscellaneous uses of poly(vinyl ester)s synthesized by RAFT, for instance as a means to produce poly(vinyl alcohol) with controlled characteristics for use in the biomedical area, are also covered.

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“…At the beginning of the polymerization, some positive deviation of M n(GPC) s from the theoretical values (M n(th) s) may be due to the incomplete usage of RAFT agent [42]. And at high monomer conversions, some negative deviation may be due to the side reactions of the initiator or initiator-derived radicals with the RAFT agent [32][33][34][35][36]40]. On the other hand, the GPC standard calibration samples of PMMA may be the other cause of some deviations for M n(GPC) from the theoretical values.…”

Section: Raft Polymerizations Of Mamp and Macpmentioning

confidence: 99%

“…However, the reaction conditions are very stringent and the range of polymerisable monomers is quite limited. The 'living'/ controlled free radical polymerization (LFRP) [28][29][30][31][32][33][34][35][36][37][38][39], developed rapidly during the past decade, was a frequently used technology in the preparation of well-defined polymers. Among the LFRP techniques, the reversible addition-fragmentation chain transfer (RAFT) polymerization is considered as one of the most versatile method with wide range of polymerisable monomer and undemanding polymerization conditions.…”

mentioning

confidence: 99%

Azo polymers with electronical push and pull structures prepared via RAFT polymerization and its photoinduced birefringence behavior

Cao¹,

Zhang²,

Zhu³

et al. 2008

Express Polym. Lett.

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Abstract. Two methacrylate monomers containing azo and electronical push and pull structure, e.g. 2-Methyl-acrylic-acid-2-{[4-(4-cyano-phenylazo)-3-methyl-phenyl]-ethyl-amino-ethyl ester (MACP) with cyano substituted and 2-Methylacrylic-acid-2-{ethyl-[4-(4-methoxy-phenylazo)-3-methyl-phenyl]-amino}-ethyl ester (MAMP) with methoxy substituted, were synthesized and polymerized using 2-cyanoprop-2-yl dithiobenzoate (CPDB) as chain transfer agent and 2,2'-azobisisobutyronitrile (AIBN) as initiator. The results showed that the polymerization displayed characteristics of 'living'/controlled free radical polymerization. Thus, the obtained polymers, polyMACP (pMACP) and polyMAMP (pMAMP), had controlled molecular weights and narrow molecular weights distribution. The chain extension experiments of pMACP and pMAMP using styrene as the second monomer were successfully carried out. The photo-induced trans-cis-trans isomerization kinetic of pMACP and pMAMP in chloroform solution were described. Marked differences in rate for the trans-cis and cis-trans isomerization of pMACP and pMAMP were observed in chloroform solution due to the different electronic effects in these two polymers. Photoinduced birefringence and surface relief grating (SRG) of the pMACP and pMAMP were investigated in thin film state. Keywords: polymer synthesis, azopolymers, photo-induced birefringence, surface relief grating (SRG), reversible additionfragmentation chain transfer polymerization (RAFT)eXPRESS Polymer Letters Vol.2, No.8 (2008) [589][590][591][592][593][594][595][596][597][598][599][600][601] Available online at www.expresspolymlett.com DOI: 10.3144/expresspolymlett.2008.71 polymers by linearly polarized (LP) photoexcitation of the azobenzene group, which undergoes trans-cis-trans isomerization [17,18] , giving rise, after repeated photoexcitation and isomerization cycles, to a net excess of azobenzene moieties oriented with their transition dipole moments perpendicularly to the direction of the pump electric field. The anisotropic distribution of chromophores provides birefringence and linear dichroism of the film can be erased by irradiation with depolarized or circularly polarized (CP) light, thus reproducing the original isotropy in the material. According to Rabek's report [19], azo compounds can be divided into three classes: azobenzene type, aminoazobenzene type and pseudo-stilbene type. Azobenzene containing compounds with electronical push and pull structures (pseudo-stilbene type) and aminoazobenzene type molecules can isomerize from cis configuration back to trans configuration very quickly at room temperature. However, the thermal cis-trans isomerization in azobenzene-type molecules is relatively slow, and it is even possible to isolate the cis isomer [20]. Typically, the azobenzene containing polymers can be obtained through two ways: incorporating azobenzene chromophores into the backbones directly during the polymerization process [21][22][23], and postpolymerization modification technique [24][25][26][27]. Generally, conv...

show abstract

Experimental Requirements for an Efficient Control of Free‐Radical Polymerizations via the Reversible Addition‐Fragmentation Chain Transfer (RAFT) Process

Cited by 433 publications

References 379 publications

Chain Transfer in Degenerative RAFT Polymerization Revisited: A Comparative Study of Literature Methods

Chain Transfer in Degenerative RAFT Polymerization Revisited: A Comparative Study of Literature Methods

RAFT Polymerization of Vinyl Esters: Synthesis and Applications

Azo polymers with electronical push and pull structures prepared via RAFT polymerization and its photoinduced birefringence behavior

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