Institut Charles Sadron News

Jean-Marie CATALA

(Research Director at CNRS)

Jean-Marie
Catala arrived at the Centre de Recherches sur les Macromolécules (CRM)
in 1972 to attend the postgraduate program on polymers at the Louis
Pasteur University in Strasbourg. He joined the Macromolecular Organic
Synthesis team led by Professor Jean Brossas. There, he completed a
third cycle thesis on the synthesis of telechelic polymers with
hydroperoxide end groups, defended in 1975, followed by a state thesis
on the action of oxygen on mono and multi carbanionic oligomers and
polymers, defended in 1980. In these early studies, he did not only
carry out polymer syntheses. He also investigated reaction mechanisms in
order to understand each step of the functionalization process through
kinetic studies, benefiting especially from discussions with Gilbert
Clouet. At a time when it was far from common, he was already routinely
using several characterization techniques such as NMR, IR and SEC. He
maintained this conscientious chemist attitude throughout his entire
career, right up to his retirement in 2012.

Jean-Marie joined the CNRS after obtaining his third cycle
doctorate. After defending his state thesis, he went to Amherst in the
United States for a one-year postdoctoral stay on thermotropic liquid
crystalline polymers. Upon returning, unable to spark lasting interest
from a CRM physicist in these polymers, he continued his research within
Jean Brossas’s team at the CRM, then at the Institut Charles Sadron
(ICS), focusing on the functionalization of macromolecules, mainly
within the broader problem of flame retardancy of polymer materials. He
studied polysulfides, proposing new syntheses of oligomers and polymers
containing sulfur atoms, as well as certain phosphonated polymers,
always conducting detailed studies of the kinetics and mechanisms of the
polymerizations involved. Since these polymers had many applications,
his research benefited from collaborations with industry. At the same
time, Jean-Marie prepared thin films of liquid polymers for surface
force and viscosity measurements carried out by physicists in the United
States.

Later, Jean-Marie set aside the flame retardancy issue,
which certainly required further physico chemical studies, to focus with
his students and the engineers of his team on controlled radical
polymerization, a field in which he obtained remarkable results and
international recognition. His contributions concern in particular
kinetic studies by EPR and the mechanisms of controlled radical
polymerization of styrene and substituted styrenes in the presence of
nitroxide radicals, with applications to the synthesis of block
copolymers. In parallel, new nitroxides and functionalized alkoxyamines
were developed for the controlled radical polymerization of vinylic
monomers, correlating the structure of the radicals with the kinetic
parameters of polymerization. This line of research eventually led to a
fruitful collaboration with researchers at the University of Liège.

Around the same time, Jean-Marie also became interested in
polymerization and chemical modification processes of polymers in
supercritical media or in the presence of supercritical CO₂.

As part of a collaboration with ICS physicists, he
undertook the synthesis of a conjugated polyacid, poly(thiophene 3
acetic acid) (P3TAA), first by oxidation to yield regio random polymers.
He then used organomagnesium metathesis with a nickel catalyst (GRIM)
to obtain polymers with controlled molar masses and full
regioregularity. True to himself, he achieved this result by
investigating the polymerization mechanisms, synthesizing new monomers
and controlling in situ initiation via UV Visible spectroscopy and NMR
titration. This made it possible to study the structure of aqueous
solutions of regio random P3TAA and to establish the link between the
electronic structure of the p electrons along the backbone and the
average conformation of these macroions, leading to an original
observation of charge instability in hydrophobic polyelectrolytes with
dynamic charge distribution, also known as the hydrophilic hydrophobic
transition in so called annealed polyelectrolytes. He also explored the
interaction of P3TAA with surfactants based on alkyltriethylammonium
bromides.

Subsequently, a collaboration with the University of Tours
and CEA Le Ripault led him, for the first time and with success, to
adapt controlled radical polymerization involving nitroxide radicals to
the synthesis of new polystyrenes bearing organometallic species, with
controlled molar masses and low polydispersities. Using anionic
polymerization, he also succeeded, again for the first time, in
preparing poly(alpha methylstyrenes) with very high controlled molar
masses and low polydispersities.

In the same collaborative spirit, he regularly synthesized
model macromolecules for fundamental physics studies conducted by
physicists and physical chemists at the ICS.

Jean-Marie Catala spent most of his career at the CNRS.
Through his original work, his collaborations with chemists and
physicists in France and abroad, as well as with industry, through his
teaching in polymer chemistry at the Louis Pasteur University and his
involvement in the GFP as president of the Grand Est section, he greatly
contributed to the influence of the CRM and later of the ICS.

Jean-Marie was an extremely curious scientist who took a
close interest in activities beyond his own research themes. In this
way, he was a cornerstone of the laboratory’s scientific life. Alongside
this scientific life, Jean-Marie was an indefatigable contributor to
the social life of the laboratory, often well into lively late evenings.
Paraphrasing the thoughts of a French filmmaker on art, one might say
that he believed that science is worth nothing without raw life within
it, and life is worth nothing without science to capture its
reflections. It is therefore no surprise that he had a precious rapport
with the youngest researchers, offering them useful advice with both
high standards and kindness.

Jean-Marie Catala passed away in his seventy seventh year,
after a long and difficult hospitalization. He fought magnificently and
courageously.