||I U P A C
Organizations & People
WORKING PARTY ON MODELLING
OF POLYMERIZATION KINETICS AND PROCESSES
Title: Critically Evaluated Database
of Kinetic Parameters for Free-Radical Polymerization - 2
Remarks: Commission IV.2
Completion Date: 2000
Modelling and mechanism of free-radical polymerizations are important
for science and industry, but often completely different model assumptions
and parameter values are reported for ostensibly the same systems.
The project is to rectify this situation through international collaboration,
by producing critically evaluated kinetic parameters, whose values
are reliable and which can be used by the international polymer
community: this is seen as fulfilling IUPAC objectives. Reliable
methodologies for the goals of the present project have been established
by the predecessor to this project, the IUPAC Working Party on "Modeling
of Polymerization Kinetics and Processes - Benchmark Rate Parameters
for Free-Radical Polymerization". Benchmark propagation rate
coefficients have been obtained for styrene and methyl methacrylate
by critical evaluation and also by independent experiments (from
at least two members of the WP). These efforts will be extended
to all other relevant monomers with these activities already being
underway for other members of the alkyl methacrylate family and
for functional and cyclic methacrylates. Propagation rate coefficients
of alkyl acrylates will subsequently be evaluated, as will be propagation
rates in copolymerizations. Moreover, termination and chain transfer
data will be evaluated by the WP. It has been decided to emphasize
methods and results from pulsed laser polymerization (PLP), and
to use these, in addition, to "benchmark" other methods.
The current focus is on PLP-SEC (size exclusion chromatography)
experiments to deduce propagation rate coefficients of free-radical
homopolymerizations. Results have been obtained for a number of
monomers by WP members. Novel criteria for the reliability of PLP
results have been set down. Strategies for planning PLP experiments
have been worked out. The experimental PLP work is accompanied by
extensive theoretical studies of pulsed laser polymerization.
Project Completed - Reports
- Critically-evaluated propagation rate coefficients in free radical
Critically evaluated rate
coefficients for free-radical polymerization
Last update: 5 February 2001
Page last modified 5 August 2001.
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