Single-electron and two-electron transfer in the anionic polymerization of vinyl monomers and the ring-opening polymerization of lactones

2002 ◽  
Vol 40 (13) ◽  
pp. 2158-2165 ◽  
Author(s):  
Zbigniew Jedli?ski
Keyword(s):  
Electron Transfer ◽  
Anionic Polymerization ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Single Electron ◽  
Vinyl Monomers

Investigations on the Combination of Cationic Ring Opening Polymerization and Single Electron Transfer Living Radical Polymerization to Synthesize 2-Ethyl-2-Oxazoline Block Copolymers

2012 ◽  
Vol 65 (8) ◽  
pp. 1132 ◽  
Author(s):  
Robert A. Young ◽  
Edward L. Malins ◽  
C. Remzi Becer
Keyword(s):  
Electron Transfer ◽  
Radical Polymerization ◽  
Ring Opening ◽  
Catalyst Concentration ◽  
Ring Opening Polymerization ◽  
Living Radical Polymerization ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Cationic Ring Opening Polymerization ◽  
Glycol Methyl Ether

Cationic ring opening polymerization of 2-ethyl-2-oxazoline (EtOx) has been performed using α–bromoisobutyryl bromide (tertiary) and 2-bromopropionyl bromide (secondary) as initiators in acetonitrile. The reaction kinetics have been followed and selected P(EtOx) polymers have been used as macroinitiators for the single electron transfer living radical polymerization (SET-LRP) of methyl acrylate (MA), ethylene glycol methyl ether acrylate and 2-(dimethylamino)ethyl methacrylate. Moreover, the effect of solvent and catalyst concentration have been investigated on the SET-LRP of P(EtOx) initiated MA.

TiCp2Cl-Catalyzed Living Radical and Ring Opening Polymerizations Initiated from Epoxides and Aldehydes in the Synthesis of Linear, Graft and Branched Polymers

2004 ◽  
Vol 856 ◽  
Author(s):  
Alexandru D. Asandei ◽  
Isaac W. Moran ◽  
Gobinda Saha ◽  
Yanhui Chen
Keyword(s):  
Electron Transfer ◽  
Ring Opening ◽  
Glycidyl Methacrylate ◽  
Ring Opening Polymerization ◽  
Branched Polymers ◽  
Single Electron Transfer ◽  
Radical Ring ◽  
Polymer Architectures ◽  
Complex Polymer

ABSTRACTTi(III)Cp2Cl-catalyzed radical ring opening (RRO) of epoxides or single electron transfer (SET) reduction of aldehydes generates Ti alkoxides and carbon centered radicals which add to styrene, initiating a radical polymerization. This polymerization is mediate in a living fashion by the reversible termination of growing chains with the TiCp2Cl metalloradical. In addition, polymers or monomers containing pendant epoxide groups (glycidyl methacrylate) can be used as substrates for radical grafting or branching reactions by self condensing vinyl polymerization. In addition, Ti alkoxides generated in situ by both epoxide RRO and aldehyde SET initiate the living ring opening polymerization of ε-caprolactone. Thus, new initiators and catalysts are introduced for the synthesis of complex polymer architectures.

scholarly journals Anionic Polymerization of β-Butyrolactone Initiated with Sodium Phenoxides. The Effect of the Initiator Basicity/Nucleophilicity on the ROP Mechanism

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1221 ◽  
Author(s):  
Adrian Domiński ◽  
Tomasz Konieczny ◽  
Magdalena Zięba ◽  
Magdalena Klim ◽  
Piotr Kurcok
Keyword(s):  
Anionic Polymerization ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Elimination Reaction ◽  
Mild Conditions ◽  
Acidic Proton ◽  
End Groups ◽  
Anionic Ring

It was shown that selected sodium phenoxide derivatives with different basicity and nucleophilicity, such as sodium p-nitrophenoxide, p-chlorophenoxide, 1-napthoxide, phenoxide and p-methoxyphenoxide, are effective initiators in anionic ring-opening polymerization (AROP) of β-butyrolactone in mild conditions. It was found that phenoxides as initiators in anionic ring-opening polymerization of β-butyrolactone behave as strong nucleophiles, or weak nucleophiles, as well as Brønsted bases. The resulting polyesters possessing hydroxy, phenoxy and crotonate initial groups are formed respectively by the attack of phenoxide anion at (i) C2 followed by an elimination reaction with hydroxide formation, (ii) C4 and (iii) abstraction of acidic proton at C3. The obtained poly(3-hydroxybutyrate) possesses carboxylate growing species. The ratio of the observed initial groups strongly depends on the basicity and nucleophilicity of the sodium phenoxide derivative used as initiator. The proposed mechanism of this polymerization describes the reactions leading to formation of observed end groups. Moreover, the possibility of formation of a crotonate group during the propagation step of this polymerization is also discussed.

Cyclic voltammetry of diphenylpicrylhydrazyl in tetrahydrofuran

1968 ◽  
Vol 46 (8) ◽  
pp. 1337-1340 ◽  
Author(s):  
B. Lionel Funt ◽  
Derek G. Gray
Keyword(s):  
Electron Transfer ◽  
Cyclic Voltammetry ◽  
Free Radical ◽  
Anionic Polymerization ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Transfer Processes ◽  
Suitable Medium ◽  
The Stability ◽  
Electron Transfer Processes

Cyclic voltammetry has revealed four reversible single electron transfer processes in the oxidation and reduction of diphenylpicrylhydrazyl (DPPH) in tetrahydrofuran (THF). These are associated with a cation, a free radical, a monoanion, a dianion radical, and a trianion of DPPH.THF is a good solvent for cyclic voltammetry as evidenced by the stability of the products generated at the electrodes. It is also one of the few excellent solvents for anionic polymerization and is therefore a remarkably suitable medium for studies of electropolymerization phenomena.

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