Number: 2002-006-2-400
Title: Terminology for radical
polymerizations with minimal termination - the so-called "living"
and/or "controlled" radical polymerization
Task Group
Chairman: Aubrey
D. Jenkins
Members: Takeshi
Fukuda, Robert
G. Gilbert, Michael
Hess, Richard G.
Jones, Pavel
Kratochvíl, Krystof
Matyjaszewski, Graeme
Moad, Kohji Ohno,
Stanislaw Penczek,
Gregory Russell,
Robert Stepto, Jean-Pierre
Vairon, and Jiri
Vohlidal
Objective:
To provide recommendations for nomenclature and terminology in relation
to modern (1994-) techniques of radical polymerisation, variously
described in the literature as, e.g., "living" and/or
"controlled".
Description:
There has been an explosion of renewed interest in radical polymerisation
during the last nine to ten years, stemming largely from the discovery
of new polymerization techniques which provide products with novel
molecular architecture, composition, and molar-mass distribution.
This burst of activity has given rise to a diverse and uncoordinated
terminology. The use of inappropriate terms, and the lack of uniformity
of practice, constitute severe impediments to intelligible communication
and effective literature-searching, with consequent potential to
retard the development of this important field.
A few recent publications have addressed
some aspects of the problem and provided suggestions for possible
terminology. These include the following:
Matyjaszewski, K. and Mueller, A. H. E.,
"Macromolecular nomenclature note No. 12. Naming of controlled,
living and "living" polymerizations", Polym. Prepr.,
38(1), 6-9 (1997).
Darling, T. R., Davis, T. P., Fryd, M.,
Gridnev, A. A., Haddleton, D. M., Ittel, S. D., Matheson, R. R.,
Jr., Moad, G. and Rizzardo, E., "Living polymerization: rationale
for uniform terminology", J. Polym. Sci., Part A: Polym.
Chem., 38, 1706-1708 (2000), (and subsequent papers in
this issue).
Ivan, B., "Macromolecular nomenclature
note No. 19. Terminology and classification of quasiliving polymerizations
and ideal living polymerizations on the basis of the logic of elementary
polymerization reactions, and comments on using the term "controlled",
Polym. Prepr. 41(2), 6a-12a (2000).
Howell, B. A., "Mediated radical
polymerization", Polym. Mater. Sci. Eng., 83,
578 (2000).
Fischer, H., "The Persistent Radical
Effect", Chem. Rev.,101, 3581 (2001).
These papers display a diversity of views:
none of the terminologies advocated has achieved widespread acceptance,
neither has any of them been adopted as IUPAC-recommended terminology.
Moreover, there are additional issues to be addressed relating to
the misapplication of classical terminology to new circumstances.
The frenzy of activity on the part of
individuals outside IUPAC to attempt to define terms, or calling
for regulated terminology, demonstrates the urgent need for an appropriate
IUPAC body to take speedy action to provide an internationally-agreed
set of terms in this field. It also shows that there is no need
for a preliminary feasibility study, which would only waste time
and allow the situation to deteriorate further.
An existing IUPAC project #2002-016-1-400
titled "Terminology for
the kinetics, thermodynamics, and mechanism of polymerization"
has touched on some of the issues proposed to be addressed by this
new working party but with much broader terms of reference. Nonetheless,
the report from this project (expected during the next few months)
will have significant value in relation to the project outlined
here.
The initial step will be to compile, and
critically evaluate, the existing terminology. There will be a need
to coordinate with, and perhaps suggest modification of, some aspects
of the terminology of conventional radical polymerisation and other
forms of polymerization (e.g., anionic, cationic, so-called group-transfer,
coordination, ring-opening, metathesis). However, the initial focus
will be directed to the area of radical polymerisation.
Most of the interaction among TaskGroup
Members will take the form of correspondence by e-mail; face-to-face
meetings/workshops will be coordinated with IUPAC General Assemblies
or international meetings in the field of polymerisation.