Free-Radical Polymerization of Styrene in Emulsion Using a Reversible Addition−Fragmentation Chain Transfer Agent with a Low Transfer Constant:  Effect on Rate, Particle Size, and Molecular Weight

2001 ◽  
Vol 34 (13) ◽  
pp. 4416-4423 ◽  
Author(s):  
Michael J. Monteiro ◽  
Jean de Barbeyrac
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Free Radical ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Free Radical Polymerization ◽  
Chain Transfer Agent ◽  
Transfer Constant ◽  
Reversible Addition

Living Free-Radical Polymerization by Reversible Addition−Fragmentation Chain Transfer:  The RAFT Process

1998 ◽  
Vol 31 (16) ◽  
pp. 5559-5562 ◽  
Author(s):  
John Chiefari ◽  
Y. K. (Bill) Chong ◽  
Frances Ercole ◽  
Julia Krstina ◽  
Justine Jeffery ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Free Radical Polymerization ◽  
Reversible Addition ◽  
Living Free Radical Polymerization

scholarly journals Methylenelactide: vinyl polymerization and spatial reactivity effects

2016 ◽  
Vol 12 ◽  
pp. 2378-2389 ◽  
Author(s):  
Judita Britner ◽  
Helmut Ritter
Keyword(s):  
Free Radical ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Free Radical Polymerization ◽  
Controlled Radical Polymerization ◽  
Experimental Results ◽  
Cyclic Monomer ◽  
Vinyl Polymerization ◽  
Reversible Addition

The first detailed study on free-radical polymerization, copolymerization and controlled radical polymerization of the cyclic push–pull-type monomer methylenelactide in comparison to the non-cyclic monomer α-acetoxyacrylate is described. The experimental results revealed that methylenelactide undergoes a self-initiated polymerization. The copolymerization parameters of methylenelactide and styrene as well as methyl methacrylate were determined. To predict the copolymerization behavior with other classes of monomers, Q and e values were calculated. Further, reversible addition fragmentation chain transfer (RAFT)-controlled homopolymerization of methylenelactide and copolymerization with N,N-dimethylacrylamide was performed at 70 °C in 1,4-dioxane using AIBN as initiator and 2-(((ethylthio)carbonothioyl)thio)-2-methylpropanoic acid as a transfer agent.

Modelling the Complete Molecular Weight Distribution in Chain Growth Polymerizations

2016 ◽  
Vol 1819 ◽  
Author(s):  
Ramiro Infante-Martínez ◽  
Enrique Saldívar-Guerra ◽  
Odilia Pérez-Camacho ◽  
Maricela García-Zamora ◽  
Víctor Comparán-Padilla
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Radical Polymerization ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Chain Transfer ◽  
Free Radical Polymerization ◽  
Experimental Program ◽  
Chain Growth ◽  
Coordination Polymerization

ABSTRACTThis work shows the development of several models for chain-growth polymerizations that admit the direct calculation of the complete molecular weight distribution of the polymer. The direct and complete calculation implies that no statistical mean values are employed as in the moments method neither numerical approximations like in the minimum-squared based methods. The free radical polymerization of ethylene (LDPE) and the coordination via metallocenes polymerization of ethylene (HDPE) are taken as examples for analysis.In the free radical polymerization case, the conventional scheme for chain-growth polymerization is adopted, with steps for initiation, propagation, chain transfer to small species and the additional step of chain transfer to dead chains [1]. The kinetic parameter are obtained from the open literature. Two kind of reactors were modelled: batch and continuous stirred tank reactor. For this last case, a simulation strategy was considered in which the run started from an initial known population of dead chains. Results show that typical non-linear polymerization profiles for the molecular weight distribution are obtained. For the coordination polymerization of ethylene via metalocenes, the standard coordination model was employed [2]. A two-site catalyst was considered and kinetic parameters reported in the open literature were used. For this study an experimental program in a lab-scale reactor was undertaken in order to obtain modelling data [3]. Results show that the standard model adequately reproduces the experimental data in the kinetic and molecular attributes of the polymer.

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