Problems of control of the reactivity of macroradicals and the growth of polymer chains

Гришин, Д. Ф.; Semyonycheva, Lyudmila L.

doi:10.1070/rc2001v070n05abeh000635

Cited by 59 publications

(18 citation statements)

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“…The "stereospecific radical polymerization" term has been suggested by the Japanese scientists to describe such processes [20,21]. However, in view of the recently reported data on the effects of structurally diverse metal-containing compounds on the radical polymerization with the character of stereoregular, complex-, and/or coordination-radical behavior [8,17,18,[22][23][24], such processes rather should be regarded as metal-complex radical polymerization, since these processes are based on the complex formation between the metal compound with the macroradical and/or monomer, resulting in the polymer chain propagation vie the cyclic reaction complex [17,18].…”

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“…in 1960ies has been recognized as being of high importance in polymers synthesis; this method allows for the similarly efficient control of the polymer chain propagation via the complex formation between halides of non-transition metals (primarily the Lewis acids) [17] or organic compounds of II-V groups elements [18] with monomers and/or macroradicals. The effect of certain Lewis acids on the stereochemical composition of the macromolecules prepared via radical polymerization has been reported [17,[19][20][21].…”

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Iron compounds in controlled radical polymerization: Ferrocenes, (clathro)chelates, and porphyrins

Islamova

2016

Russ J Gen Chem

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Abstract-Experimental data on the application of metal complexes in radical polymerization of vinyl monomers collected over the recent 15 years have been analyzed and generalized. Special attention has been given to (un)substituted ferrocenes, macrocyclic (clathro)chelates, and iron porphyrinates as well as to the approaches to enhance their catalytic activity in controlled synthesis of macromolecules. The mentioned systems have been compared with each other as well as with selected complexes of other transition metals. It has been shown that the electronic and spatial structures of the metal complexes are related to their efficiency in the radical polymerization reactions. Keywords: controlled radical polymerization, metallocene, (clathro)chelate, metal porphyrinate, catalytic/ initiating system Application of metal complexes opens broad prospects to control the polymerization processe and to prepare polymer materials with improved physicochemical properties. The metal complex catalysis has become of special importance in the field of controlled radical polymerization over the recent 15 years.The term "controlled radical polymerization" is generally referred to "living" or "pseudo-living" radical polymerization; its mechanism, irrespectively of the type of the catalysts/mediators applied (metal complexes [1-11], nitroxyl compounds [12-14], thioesters [15,16], etc.) is based on minimization of the probability of the interaction between the propagating radicals, resulting in the irreversible chain termination. This allows for control of molecular parameters of the prepared polymers, in particular, reduction of the polydispersity coefficient down to M w /M n = 1.1, achieving the linear behavior of the number-average molecular mass (M n ) as function of the conversion, elimination of the undesirable gel effect, and preparation of block copolymers.Atom Transfer Radical Polymerization (ATRP) [1], Transition Metal-Catalyzed Living Radical Polymerization [7], and Organometallic Mediated Radical Polymerization (OMRP) [11] are among the types of controlled radical polymerization. The first approach is based on the use of halides of organic complexes of transition metals, leading to the formation of labile terminal carbon-halogen bond (P n -Hlg). Under certain conditions, this bond is capable of dissociation to regenerate the initial or new active radical further propagating the polymer chain (Scheme 1).Here P n · stands for the propagating macroradical, М is the vinyl monomer, HlgMt x+1 /L is the metal complex halide (with L as the organic ligand), Mt is the transition metal, and k p is the rate constant of the chain propagation.The second of the listed methods uses stable radical organometallic species or diamagnetic transition metal complexes forming the carbon-metal bond P n -Mt as the regulators of the polymer chain growth [11] (Scheme 2).Due to the similarity of these two approaches their simultaneous operation is often assumed [11].Besides "living" radical polymerization, complexand/or coordination-radical polymeri...

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Iron compounds in controlled radical polymerization: Ferrocenes, (clathro)chelates, and porphyrins

Islamova

2016

Russ J Gen Chem

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“…2,3 According to literature data, diphenylbutadiene (i.e. the organic derivative of DPC) easily gives the corresponding diphenylbutadienyl anions in the presence of sec-butyl lithium, 15 and is inert into the 1-cyano-1-methylethyl radical.…”

Section: Scheme 1 R: a Growing Radicalmentioning

confidence: 99%

“…without autoacceleration and with the synthesis of polymers of the desired molecular weight characteristics. 1,2 Stable radicals and their sources, 3,4 including organometallic additives, 5,6 have been actively employed recently in chain propagation regulators in radical initiation. In particular, α-methylstyrene chromium tricarbonyl and allylbenzene chromium tricarbonyl were reported to influence chain propagation in the polymerization of methylmethacrylate (MMA), styrene and butyl acrylate.…”

Section: Introductionmentioning

confidence: 99%

Diphenylbutadiene chromium tricarbonyl in radical polymerization of methylmethacrylate

Valetova

Semyonycheva

Illichev

et al. 2005

Appl. Organometal. Chem.

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“…('atom transfer radical polymerization') (ATRP), 'reversible addition-fragmentation chain transfer' (RAFT) and the application of nitroxide stable radicals 'nitroxide-mediated polymerization' (NMP)' including their generation in situ during polymerization. 1,3 In the latter case, active additives such as nitroso compounds, nitrones, etc. are introduced to the polymerizing medium to carry out the controlled process.…”

Section: Introductionmentioning

confidence: 99%

Vinylarenetricarbonyl complexes of chromium as chain propagation regulators for polymerization of acrylic monomers

Гришин

Semyonycheva

Artemov

et al. 2003

Applied Organom Chemis

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The polymerization of methyl methacrylate and butyl acrylate initiated by azo-bis-isobutyronitrile in the presence of metal-containing monomers (p-methylstyrene-, stilbene-and α-methylstyrenechromiumtricarbonyl) was studied. Kinetic parameters (i.e. the decrease in the autoacceleration during the polymerization of acrylic monomers, its shift towards a high conversion region in the presence of α-methylstyrenechromiumtricarbonyl, a linear dependence of the molecular weight of a polymethyl methacrylate and the shift of molecular-weight distribution curves to a high molecular weight region with conversion) demonstrate the influence of vinylarenetricarbonyl complexes of chromium on basic steps of polymerization. It is important to note that the above organometallic compounds enable the controlled synthesis of polymers under temperature conditions (50-70 • C) corresponding to those of the industrial polymer production.

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Problems of control of the reactivity of macroradicals and the growth of polymer chains

Cited by 59 publications

References 56 publications

Iron compounds in controlled radical polymerization: Ferrocenes, (clathro)chelates, and porphyrins

Iron compounds in controlled radical polymerization: Ferrocenes, (clathro)chelates, and porphyrins

Diphenylbutadiene chromium tricarbonyl in radical polymerization of methylmethacrylate

Vinylarenetricarbonyl complexes of chromium as chain propagation regulators for polymerization of acrylic monomers

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