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Polymerization and polymer modification in supercritical fluids - a novel way for cleaner manufacturing of plastics


Objectives and content
Any polymerisation process employed for the production of
plastics can generate large amounts of hazardous waste in
the form of organic solvents, which may be hazardous on
their own together with leftover monomer(s) and
initiator(s). Even if the original solvent is plain
water, the waste (contaminated water) is considered
environmentally dangerous. The dissemination of chemical
waste (volatile organic compounds, chlorofluorocarbons,
and aqueous-waste streams) into our environment has
prompted considerable world-wide concern, and
environmental issues are now of paramount interest to the
chemical industry. The present multi-disciplinary
research programme aims at the design of new
polymerisation processes for the manufacture and chemical
modification of polymeric materials using
supercriticalfluids (e g., CO2) as the dispersing medium.
The transacted research will be directed towards the
synthesis and characterization of novel polymeric
stabilisers that enhance the solubilizing properties of
carbon dioxide, which are crucial for its widespread
application. Novel chemically- or gamma irradiationinitiated free-radical and ring-opening polymerisation
processes will be developed for the production of
polymeric materials (homo- and copolymers of PVDF,
polycaprolactone) using supercritical CO2 as the
dispersing medium. In order to improve the performance
of existing polymeric materials, chemical modification of
swollen particles of prefabricated polymers (e.g.
polyolefins, polycondensates, styrene-maleic anhydride
copolymers) in supercritical fluids will also be carried
out. Specifically, the research efforts will be focused
on the following scientific and industrial objectives:
Development of novel amphiphatic block, graft and starshaped copolymers. These copolymers will be employed as
surfactants for carrying out polymerisation reactions in
scCO2. They can also be used for surface modification of
textiles and thermoplastics in order to improve soil
repellency and friction properties of polymer surfaces.
Development of environmentally friendly polymer
manufacturing technologies by using i.e. scCO2 as the
dispersing medium for the synthesis of a new generation
of PYDF and other fluoropolymers.
Preparation of environmentally friendly biodegradable
aliphatic polyesters, commonly designated as green
polymers, in sc fluids.
Development of non-conventional methodologies such as
ionising radiation for initiating polymerisation
reactions and for the modification of prefabricated
Development of new technologies for the chemical
modification of swollen polymer particles in C02
dispersions or in other sc fluids. The new technologies
differ from the high-temperature melt modification
process which often results in undesired side reactions
and degradation, and from the modification in solution
process in which major amounts of solvents are required,
thus, making the process highly unfavourable from an
economical point of view.
Development of quantitative models combining
thermodynamics and polymerisation kinetics to describe
the supercritical polymerisation processes.
In addition, the proposed methodologies will lead to:
Elimination of the production of organic and aqueous
waste streams generated in the classical polymer
manufacturing processes.
Synthesis of highly purified products by the in situ
separation of small amounts of unreacted monomers, highly
toxic initiator residues, decomposition products, etc.,
using supercritical fluid extraction (SCFE) processes.
Integration of reaction and separation processes:
substantial energy savings are expected by the relative
ease with which the solvent can be separated from the
The proposal conforms with Point 1.2 of the workprogramme
(Development of Clean Production Technologies) and the
Principal Research Tasks 1.2.1.S (Substitution of
hazardous industrial and processing materials such as
organic solvents and other harmful compounds), 1.2.3.S
(Incorporation of new technologies and materials into
production processes for significant limitation of
overall pollution and waste at production sites), and
1.2.2.M (Development of new efficient and/or
environmentally benign production and processing


Aristotle University of Thessaloniki
University Campus
54006 Thessaloniki

Participants (6)

DSM Research BV
6160 MD Geleen
Solvay S.A.
310,Rue De Ransbeek
1120 Bruxelles
Th. Goldschmidt AG
45127 Essen
3,Allée De La Chimie 3 Institut De Chimie B6 Allée
4000 Liege
Albert Einstein Allee 11
89069 Ulm
Viale Delle Scienze
90128 Palermo