Nitroxide-Mediated Radical Polymerization in Nanoreactors: Can Dilution or Increased Nitroxide Concentration Provide Benefits Similar to Compartmentalization?

2010 ◽  
Vol 63 (8) ◽  
pp. 1195 ◽  
Author(s):  
Per B. Zetterlund
Keyword(s):  
Radical Polymerization ◽  
Polymerization Rate ◽  
Confined Space ◽  
Segregation Effect ◽  
Polymerization System ◽  
Space Effect ◽  
Modelling And Simulations ◽  
The Cost

Compartmentalization of a nitroxide-mediated radical polymerization system can lead to improved levels of both control and livingness, but at the cost of a reduced polymerization rate. Improved control is a result of the confined space effect on deactivation, whereas improved livingness stems from the segregation effect on bimolecular termination. Modelling and simulations have been carried out for the systems styrene/2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) and styrene/2,2,5-trimethyl-4-phenyl-3-azahexane-3-oxy (TIPNO) using the respective nitroxide-based polystyrene macroinitaitors (alkoxyamines) at 125°C to elucidate whether similar benefits can be obtained in the corresponding bulk polymerizations by merely diluting the systems or by addition of extra free nitroxide. The results have shown that neither approach leads to simultaneous improvement in control and livingness relative to the corresponding bulk systems, thus accentuating the merits of compartmentalization in nanoreactors.

Viscosity effects in the free-radical polymerization of methyl methacrylate

1977 ◽  
Vol 357 (1689) ◽  
pp. 183-192 ◽  
Keyword(s):  
Free Radical ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Kinetic Scheme ◽  
Translational Diffusion ◽  
Chain Termination ◽  
Polymerization Rate ◽  
Solution Viscosity ◽  
Viscosity Effects ◽  
Free Radical Initiator

Methyl methacrylate has been polymerized in the presence of poly(methyl methacrylate) by using a free-radical initiator. The efficiency of the initiator is shown to be independent of the viscosity. At high viscosities, chain termination was influenced by the rate of translational diffusion of the polymer radicals. The dependence of the polymerization rate on viscosity is less than that predicted by a simple kinetic scheme. It appears that only those radicals which are above a certain size have their chain termination reactions controlled by the solution viscosity. This limiting size decreases as the viscosity increases.

Assessing the Importance of Diffusion‐Controlled Effects on Polymerization Rate and Molecular Weight Development in Nitroxide‐Mediated Radical Polymerization of Styrene

2007 ◽  
Vol 44 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Martha Roa‐Luna ◽  
Martha Patricia Díaz‐barber ◽  
Eduardo Vivaldo‐Lima ◽  
Liliane M.F. Lona ◽  
Neil T. McManus ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Polymerization Rate ◽  
Diffusion Controlled

A reexamination of the method for determining radical polymerization rate constants

1981 ◽  
Vol 14 (1) ◽  
pp. 227-228 ◽  
Author(s):  
Tamio Yasukawa ◽  
Kenkichi Murakami
Keyword(s):  
Radical Polymerization ◽  
Rate Constants ◽  
Polymerization Rate

Effect of initiator type and concentration on polymerization rate and molecular weight in the bimolecular nitroxide-mediated radical polymerization of styrene

2010 ◽  
Vol 29 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Telma Regina Nogueira ◽  
Maria Cecília Gonçalves ◽  
Liliane Maria Ferrareso Lona ◽  
Eduardo Vivaldo-Lima ◽  
Neil McManus ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Polymerization Rate
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