Preparation of polymer with controlled molecular weight up to high conversion using methyl 2-bromomethylacrylate as a chain transfer agent in radical polymerization

1993 ◽  
Vol 31 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Bunichiro Yamada ◽  
Selya Kobatake ◽  
Shuzo Aoki
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Chain Transfer Agent ◽  
High Conversion ◽  
A Chain

scholarly journals Further Effects of Chain-Length-Dependent Reactivities on Radical Polymerization Kinetics

2007 ◽  
Vol 60 (10) ◽  
pp. 754 ◽  
Author(s):  
Johan P. A. Heuts ◽  
Gregory T. Russell ◽  
Gregory B. Smith
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Chain Length ◽  
Chain Transfer ◽  
Transfer Constant ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
A Chain ◽  
Chain Transfer Constant ◽  
Independent Chain

In the present paper, we finalize some threads in our investigations into the effects of chain-length-dependent propagation (CLDP) on radical polymerization kinetics, confirming all our previous conclusions. Additionally, and more significantly, we uncover some unexpected and striking effects of chain-length-dependent chain transfer (CLDTr). It is found that the observed overall rate coefficients for propagation and termination (and therefore the rate of polymerization) are not significantly affected by whether or not chain transfer is chain-length dependent. However, this situation is different when considering the molecular weight distributions of the resulting polymers. In the case of chain-length-independent chain transfer, CLDP results in a considerable narrowing of the distribution at the low molecular weight side of the distribution in a chain-transfer controlled system. However, the inclusion of both CLDP and CLDTr yields identical results to classical kinetics – in these latter two cases, the molecular weight distribution is governed by the same chain-length-independent chain transfer constant, whereas in the case of CLDP only, it is governed by a chain-length-dependent chain transfer constant that decreases with decreasing chain length, thus enhancing the probability of propagation for short radicals. Furthermore, it is shown that the inclusion of a very slow first addition step has tremendous effects on the observed kinetics, increasing the primary radical concentration and thereby the overall termination rate coefficient dramatically. However, including possible penultimate unit effects does not significantly affect the overall picture and can be ignored for the time being. Lastly, we explore the prospects of using molecular weight distributions to probe the phenomena of CLDP and CLDTr. Again, some interesting insights follow.

scholarly journals Correction: Tacticity, molecular weight, and temporal control by lanthanide triflate-catalyzed stereoselective radical polymerization of acrylamides with an organotellurium chain transfer agent

2020 ◽  
Vol 11 (46) ◽  
pp. 7439-7441
Author(s):  
Yuji Imamura ◽  
Takehiro Fujita ◽  
Yu Kobayashi ◽  
Shigeru Yamago
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Chain Transfer Agent ◽  
Temporal Control

Correction for ‘Tacticity, molecular weight, and temporal control by lanthanide triflate-catalyzed stereoselective radical polymerization of acrylamides with an organotellurium chain transfer agent’ by Yuji Imamura et al., Polym. Chem., 2020, DOI: 10.1039/d0py01280g.

scholarly journals Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

2016 ◽  
Vol 12 ◽  
pp. 2495-2502 ◽  
Author(s):  
Kohei Koyanagi ◽  
Yoshinori Takashima ◽  
Takashi Nakamura ◽  
Hiroyasu Yamaguchi ◽  
Akira Harada
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Complex Formation ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Reaction Yield ◽  
Host Molecule ◽  
Narrow Molecular Weight Distribution ◽  
X Ray ◽  
A Chain

Supramolecular catalysts have received a great deal of attention because they improve the selectivity and efficiency of reactions. Catalysts with host molecules exhibit specific reaction properties and recognize substrates via host–guest interactions. Here, we examined radical polymerization reactions with a chain transfer agent (CTA) that has α-cyclodextrin (α-CD) as a host molecule (α-CD-CTA). Prior to the polymerization of N,N-dimethylacrylamide (DMA), we investigated the complex formation of α-CD with DMA. Single X-ray analysis demonstrated that α-CD includes DMA inside its cavity. When DMA was polymerized in the presence of α-CD-CTA using 2,2'-azobis[2-(2-imidazolin-2-yl)propane dihydrochloride (VA-044) as an initiator in an aqueous solution, poly(DMA) was obtained in good yield and with narrow molecular weight distribution. In contrast, the polymerization of DMA without α-CD-CTA produced more widely distributed polymers. In the presence of 1,6-hexanediol (C6 diol) which works as a competitive molecule by being included in the α-CD cavity, the reaction yield was lower than that without C6 diol.

Tacticity, molecular weight, and temporal control by lanthanide triflate-catalyzed stereoselective radical polymerization of acrylamides with an organotellurium chain transfer agent

2020 ◽  
Vol 11 (44) ◽  
pp. 7042-7049 ◽  
Author(s):  
Yuji Imamura ◽  
Takehiro Fujita ◽  
Yu Kobayashi ◽  
Shigeru Yamago
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Acid Catalyst ◽  
Chain Transfer Agent ◽  
Temporal Control

Ternary control over molecular weight, tacticity, and time was achieved in the polymerization of acrylamides by photo-induced organotellurium-mediated radical polymerization (TERP) in the presence of Y(OTf)3 or Yb(OTf)3 as an acid catalyst.

Synthesis and degradation of branched, photo-labile poly(acrylic acid) and polystyrene

2019 ◽  
Vol 10 (5) ◽  
pp. 593-602 ◽  
Author(s):  
O. Eckardt ◽  
S. Seupel ◽  
G. Festag ◽  
M. Gottschaldt ◽  
F. H. Schacher
Keyword(s):  
Free Radical ◽  
Acrylic Acid ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Free Radical Polymerization ◽  
Chain Transfer Agent ◽  
A Chain ◽  
Synthesis And Degradation ◽  
Poly Acrylic Acid

We present the synthesis, characterization and photolytical degradation of branched photo-responsive poly(acrylic acid) and polystyrene using free radical polymerization of acrylic acid/styrene in the presence of a newly synthesized asymmetric o-nitrobenzyl-based crosslinker and different amounts of dodecanethiol (DDT) as a chain transfer agent.

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