Chemistry International
Vol. 23, No.3
May 2001
New
Projects
Critically Evaluated Termination Rate Coefficients for Free-Radical
Polymerization.1. Current Status, Evaluation of Experimental Methods,
Data for Styrene and Methyl Methacrylate
Free-radical polymerization (FRP) has always been a scientifically
and commercially important field. This importance is set to increase
even further owing to recent advances such as the development of "controlled
radical polymerization". Hence, it is of great benefit for both science
and industry to be able to model the kinetics of FRP systems. Such modeling
is dependent on the availability of reliable values of rate coefficients,
but attaining such values is not as straightforward as one might suppose.
An IUPAC Working Party on Modeling of Polymerization Kinetics and Processes
has outlined the reasons for this situation [1,2] and has begun to rectify
it with regard to propagation rate coefficients [3-5]. Now this process
will be started for termination rate coefficients, k t .
This collaborative project, supported by IUPAC' s Macromolecular Division
(IV), brings together experts in the field in order to fulfill the following
goals:
- To make workers aware of the subtleties involved in studying and
describing the termination reaction;
- To carry out an evaluation of methods for determining k t , arriving
at agreement regarding the strengths and weaknesses of each method;
and
- To come up with critically evaluated k t values for the initial
stages of bulk polymerization of styrene and methyl methacrylate,
two otherwise well-characterized systems.
This project is being chaired by Dr. Greg Russell, who may be contacted
at: Department of Chemistry, University of Canterbury, Private Bag 4800,
Christchurch, New Zealand; Tel.: +64 3 364 2458; Fax: +64 3 364 2110;
E-mail [email protected]. ac.nz. Comments and suggestions will
be welcomed. See http://www.iupac.org/projects/2000/2000-028-1-400.html
for project description and update.
1. M. Buback, L. H. Garcia-Rubio, R. G. Gilbert, D. H.Napper, J. Guillot,
A. E. Hamielec, D. Hill, K. F.O' Driscoll, O. F. Olaj, J. Shen, D. Solomon,
G. Moad, M. Stickler, M. Tirrell, M. A. Winnik. J. Polym. Sci.,Polym.
Lett. Ed. 26, 293 (1988).
2. M. Buback, R. G. Gilbert, G. T. Russell, D. J. T. Hill, G. Moad,
K. F. O' Driscoll, J. Shen, M. A. Winnik. J. Polym. Sci., Polym. Chem.
Ed. 30, 851 (1992).
3. M. Buback, R. G. Gilbert, R. A. Hutchinson, B. Klumperman, F.-D.
Kuchta, B. G. Manders, K. F. O' Driscoll, G. T. Russell, J. Schweer.
Macromol. Chem. Phys. 196, 3267 (1995).
4. S. Beuermann, M. Buback, T. P. Davis, R. G. Gilbert, R. A. Hutchinson,
O. F. Olaj, G. T. Russell, J. Schweer, A. M. van Herk. Macromol. Chem.
Phys. 198, 1545 (1997).
5. S. Beuermann, M. Buback, T. P. Davis, R. G. Gilbert, R. A. Hutchinson,
A. Kajiwara, B. Klumperman, G. T. Russell. Macromol. Chem. Phys. 201,
1355 (2000).