radical polymerization kinetics and mechanism

[...]... free -radical polymerization - Heterogeneous polymerization - Controlled radical polymerization - Polymer reaction engineering - Polymer characterization We are pleased to see that SML IV again marked an important step forward toward the better understanding of the kinetics and mechanism of radical polymerization, which is extremely relevant for both conventional and controlled radical polymerization and. .. monomer, polymer, and free -radical species and the associated ionic interactions The first studies into the kinetics of free -radical polymerization in aqueous phase date back to the work of Katchalsky and coworkers in the early 1950s.[3] In the 1970s and 1980s, polymerizations in aqueous solution were investigated by the Russian school, as reviewed by Gromov et al.[4,5] Generally, polymerizations in... ‘‘Foundation Emulsion Polymerization ’ (SEP) and by the European Graduate School on ‘‘Microstructural Control in FreeRadical Polymerization ’ M Buback, A M Van Herk ß 2007 Wiley-VCH Verlag GmbH & Co KGaA, Weinheim www.ms-journal.de Macromol Symp 2007, 248, 1–11 DOI: 10.1002/masy.200750201 The Cutthroat Competition Between Termination and Transfer to Shape the Kinetics of Radical Polymerization Gregory... Kinetic Modelling Procedure In order to determine the values of hkti and hkpi for varying reaction conditions, it can be seen from Eqs 3 and 4 that we need to know the individual rate coefficients ki;j and t kip and the radical distribution (i.e., [Ri] for all i) The individual rate coefficients are known from Eqs 7 and 8, and the radical distribution can be determined using an iterative procedure for... kinetic and mechanistic aspects of free -radical polymerization and of controlled radical polymerization The first SML meeting was organized by Ken O’Driscoll and Saverio Russo at Santa Margherita Ligure (Italy) in May 1987 The second SML meeting was held at the same location by the same organizers in 1996 The third SML meeting was organized ¨ in 2001 by Michael Buback from Gottingen University and by... on the length of the reacting radical. [1] Furthermore, it has been known that the rate-determining processes for the termination of small and long radicals are center-of-mass and segmental diffusion, respectively These processes scale with the chain length as iÀe, where e % 0.5 and 0.16 for the former and latter processes respectively It is also known that two monomeric radicals undergo a termination... ‘‘half-life’’) Available data thus far suggest C1 % 10–50 and i1/2 % 0.5–1.5;[5] for MMA polymerization we found values of C1 ¼ 15.8 and i1/2 ¼ 1.12 These latter values were obtained by fitting pulsed laser polymerization data obtained by Van Herk and co-workers[10] and were found to describe well our (independently obtained) experimental steady state data (both rates and molecular weight distributions).[3,4] In... conference heading The symposium nevertheless remains the number one forum where kinetic and mechanistic issues are addressed in detail and depth for the entire field of radical polymerization Several important aspects of radical polymerization have first been presented at SML con- ferences, e.g., the groundbreaking pulsed– laser polymerization – size-exclusion chromatography method for the reliable measurement... Dependence of hkpi on DPn, with (a) C1 ¼ 10 and i1/2 ¼ 0.5 (&), 1.0 ( ) and 5 (~); (b) with C1 ¼ 50 and i1/2 ¼ 0.5 (&), 1.0 (*) and 5 (~) Full and dotted lines are the fits according to Eqs 12 and 13 respectively  Copyright ß 2007 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim www.ms-journal.de 18 Macromol Symp 2007, 248, 12–22 ‘‘two-state’’ propagation model used by Van Herk and co-workers (Eq 10),[10] we derived... describe the true CLDP behaviour and therefore we modified it to incorporate two fit parameters Q and a (Eq 13) The corresponding data fits are also shown in Figure 5b and it is immediately clear that Eq 13 performs much better in describing the data than does Eq 12 In Table 1, all fit parameters for Eqs 12 and 13 to all combinations of C1 ¼ 10, 20 and 50 and i1/2 ¼ 0.5, 1.0 and 5.0 are listed   kp ¼ QDPÀa . toward the better understanding of the kinetics and mechanism of radical polymerization, which is extremely relevant for both conventional and controlled radical polymerization and forpeopleinacademiaaswellasinindustry. The. the better understanding of the kinetics and mechanism of radical polymerization, which is extremely relevant for both conventional and con- trolled radical polymer ization and for people in. Heppenheim ß 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Radical Polymerization: Kinetics and Mechanism Il Ciocco (Italy), September 3–8, 2006 Preface M. Buback, Alex van Herk Fundamentals of Radical