Project Details Critically evaluated rate coefficients for radical polymerizations of styrene

Project No.:
Start Date:
01 November 2013
End Date:
Division Name:


The objective is to provide a complete set of rate coefficients of all elementary reactions that are relevant for modeling of polymerization processes of a well-studied monomer of high industrial importance.


Polystyrene is one of the most studied polymers in the academic world and has numerous technical applications. In order to optimize existing technical processes, to identify new and sustainable production routes, and to develop new materials with tailored properties, first-principles modeling of conventional and reversible-deactivation (otherwise known as living/controlled) radical polymerizations is an important objective for polymer science and industry. Since polymer properties are tightly correlated with the polymerization conditions, extensive modeling at largely varying conditions is required. The knowledge of reliable rate coefficients for all elementary reactions is an indispensible requirement for reaching this goal. For measurement of individual propagation rate coefficients, kp, the IUPAC Subcommittee on “Modeling of Polymerization Kinetics and Processes” recommended pulsed-laser (initiated) polymerization (PLP) in conjunction with size-exclusion chromatography (SEC) as the method of choice. Based on this method a set of benchmark data for styrene propagation rate coefficients was published in 1995 (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, 3267-3280; The exceptional number of citations (508 as of July 2013) of this IUPAC work demonstrates the high importance of this monomer for scientific and industrial applications. However, knowing one relevant parameter is not sufficient for reliable modeling or prediction, for which purposes one actually requires a complete set of parameters. Therefore, within the present project all other relevant rate coefficients will be identified and collated. Then, a critical evaluation of the methods and existing data will be performed. Finally, a complete set of reliable kinetic data for the radical polymerization of styrene will be published. The focus will be on providing data that is suitable for implementation in modeling software. The successful completion of this project will lead to the same exercise being carried out for further monomers.


Sep 2017 update – After some long periods of no activities, the project is now reactivated with the scope of being completed within two years. After collection of data until early summer 2018, discussions are planned to take place at the MACRO2018 conference which several of the project members plan to attend.

March 2020 update – The Task Group has been re-organized, and the duration of the project has been extended until end of 2021. A common database for paper collection and as a platform to work on common documents has been established under Sharepoint. Subgroups are installed to address the following aspects in styrene polymerization:
– Initiation
– Propagation
– Termination
– Transfer
– Depropagation, Chain degradation, scission
– Physical / thermodynamic data, of monomer and polymer
– Computational methods

Documents on these topics will be prepared by the subgroups and then unified to the final document.

Last update 18 May 2020