Controlled radical polymerization initiated by stable radical terminated polytetrahydrofuran

SUMMARY: Poly(oxyethylene)s terminated at both ends with 2-bromopropionate end-groups were prepared and characterized by means of MALDI TOF mass spectrometry. It was shown, that atom transfer radical polymerization (ATRP) of methyl methacrylate with a poly(oxyethylene) macroinitiator in bulk proceeds with low initiation efficiency while polymerization of tert-butyl acrylate proceeds with practically quantitative initiation, leading to ABA block copolymers. Originally formed tert-butyl acrylate blocks contain terminal bromine, as expected for the ATRP mechanism. MALDI TOF analysis indicates, however, that in the later stages of polymerization side reactions lead to elimination of terminal bromine.

Section: Introductionmentioning

confidence: 99%

Synthesis of block copolymers by atom transfer radical polymerization oftert-butyl acrylate with poly(oxyethylene) macroinitiators

Bednarek

Biedroń

Kubisa³

1999

“…[ 10 , 11 ] Several strategies such as use of dual functional initiators [12][13][14][15][16] and propagating chain end switches [17][18][19][20][21] have been proposed and successfully applied. Previous efforts in this laboratory have focused on the development of the transformations involving combinations of free radical systems with anionic, [ 22 ] activated monomer, [ 23 ] cationic, [24][25][26] free radical promoted cationic, [27][28][29] and condensation [ 30 ] polymerizations. In some cases, the same polymerization mechanisms but different initiating systems were also employed.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Block Copolymers by Combination of Atom Transfer Radical Polymerization and Visible Light‐Induced Free Radical Promoted Cationic Polymerization

Kahveci

Açık

Yaǧcı

2012

A new synthetic approach for the preparation of block copolymers by mechanistic transformation from atom transfer radical polymerization (ATRP) to visible light-induced free radical promoted cationic polymerization is described. A series of halide end-functionalized polystyrenes with different molecular weights synthesized by ATRP were utilized as macro-coinitiators in dimanganese decacarbonyl [Mn(2) (CO)(10) ] mediated free radical promoted cationic photopolymerization of cyclohexene oxide or isobutyl vinyl ether. Precursor polymers and corresponding block copolymers were characterized by spectral, chromatographic, and thermal analyses.

“…[11] Transformation of the initiating sites was achieved by the thermal decomposition of an azo-linked poly(tetrahydrofuran) in the presence of TEMPO. The subsequent polymerization of styrene by means of TEMPO-terminated poly(tetrahydrofuran) leads to block copolymers possessing sequences prepared in a controlled manner and with overall narrow polydispersity.…”

Section: Introductionmentioning

confidence: 99%

Electron Transfer Reactions of Radical Anions with TEMPO: A Versatile Route for Transformation of Living Anionic Polymerization into Stable Radical‐Mediated Polymerization

Cianga

Senyo

Ito

et al. 2004

Summary: The possibility of transforming a living anionic polymerization into a stable radical‐mediated radical polymerization (SFRP) was demonstrated. For this purpose, 2,2,6,6‐tetramethylpiperidine‐N‐oxyl (TEMPO) alcoholate, formed by a one‐electron redox reaction between potassium naphthalene and TEMPO, was used to initiate the living anionic polymerization of ethylene oxide (EO). Poly(ethylene oxide) obtained in this way possessed TEMPO terminal units and was subsequently used as an initiator for the SFRP of styrene to give block copolymers.A one‐electron redox reaction gives rise to TEMPO alcoholate, which is able to initiate the living anionic polymerization of ethylene oxide (EO).imageA one‐electron redox reaction gives rise to TEMPO alcoholate, which is able to initiate the living anionic polymerization of ethylene oxide (EO).