Chemistry International
Vol. 24, No. 5
September 2002
New Books
and Publications
Free-Radical
Polymerization: Kinetics and Mechanism
M. Buback
and A. L. German, editors
Macromolecular Symposium,
Vol. 182, pp. 1-303, 2002. Wiley-VCH, 2002, ISBN 3-527-30472-x
Nowadays,
many polymerization processes of commercial interest are based on the
free-radical principle. The free-radical process is often preferred
over other methods of preparation as it is rather robust and less sensitive
to trace amounts of impurities. However, until the late 1980s the prevailing
opinion was that free-radical polymerization was a mature technique,
unable to afford polymers with well-defined structures, and lacking
the ability to yield narrow molecular weight distributions and block
copolymers.
In 1985,
a small group of chemists discussed the possibility of holding a meeting
devoted to radical polymerization. Chemists Ken ODriscoll and
Saverio Russo organized such a conference (SML-87) in Santa Margherita
Ligure, Italy, in May 1987. It was a great success, demonstrating that
there was indeed a renaissance in the radical polymerization field,
and it catalyzed an even stronger resurgence immediately afterwards.
In May
1996 the second conference (SML-96) of the same title was held, again
in Santa Margherita Ligure, and again arranged by ODriscoll and
Russo. The IUPAC-Sponsored "International Symposium on Free- Radical
Polymerization: Kinetics and Mechanism" (SML01), held in
June 2001 in Ciocco, Tuscany, was the third conference in the series,
and continued the tradition of holding these meetings in Italy.
SML01
was attended by 235 scientists from 25 countries, with a good balance
between attendees from industry and academia. It is also noteworthy
that quite a large number of Ph.D. students, mostly from European countries,
attended and actively participated in the scientific program.
During
the five-day program, 23 invited main lectures, 11 contributed papers,
and 135 posters were presented. Most of the main lectures and some of
the short lectures are in this issue of Macromolecular
Symposia.
The symposium
comprised six major themes:
- Fundamentals
of Free-Radical Polymerization
- Free-Radical
Polymerization in Supercritical Fluids
- Polymer
Characterization
- Polymer
Reaction Engineering
- Controlled
Radical Polymerization
- Polymerization
in Heterogeneous Systems
In looking
back, it is striking that not a single paper at SML-87 dealt with "living
radicals" (in the current sense of the term), Atom Transfer Radical
Polymerization or Reversible Addition Fragmentation Chain. At the second
meeting, SML-96, these topics were addressed in only a small number
of papers. But at SML0l, they dominated large sections of the
program.
Through
this series of three conferences, important lines of development become
clearly visible:
- Our
knowledge of the basic kinetics and mechanisms of free-radical polymerization
has increased tremendously over the past years, due to the advent
of new powerful experimental techniques like pulsed laser polymerization
and advanced mass spectrometry.
- The
explanations of anomalies in traditional radical polymerization kinetics
have been couched in terms that have tended partially to shift from
termination towards propagation.
- The
overwhelming progress in the area of "Controlled (or Living)
Radical Polymerization" (CRP), has created a more definable link
between polymerization conditions and polymer (micro) structure.
- Hand
in hand with the rapid developments in the chemistry of CRP and in
the understanding of its kinetics and mechanisms, increasing attention
is being given to emulsion systems, which will facilitate the commercialization
of CRP.
The above
advances now offer the opportunity to introduce high degrees of control
over physical and chemical properties through the manipulation of molecular
weight, polydispersity, intramolecular chemical composition distribution,
glass transition temperature, branching and branching distribution,
particle morphology in heterogeneous systems, and the incorporation
of functional groups. Improved control over the resultant properties
will lead to more efficient polymer production and new polymer products.
www.iupac.org/publications/macro/2002/182_preface.html