Influence of the Processes Parameters on the Properties of The ...

Chapter 4.
Experimental Procedures and Protocols for Analyses
poured into a petri dish. The petri dish is kept at room temperature for 48 hours, so that <strong>the</strong> solvent may
evaporate completely. After complete drying, thick film <strong>of</strong> polymer matrix is pealed <strong>of</strong>f from <strong>the</strong> petri dish.
By using die cutter pellets <strong>of</strong> <strong>the</strong> polymer matrix <strong>of</strong> required diameter (8, 10, 12 and 14 mm) are processed
(cf. Figure 4.9).
Polymer powder
A
Acetone Chlor<strong>of</strong>orm
Water bath with
<strong>the</strong>rmostat
Pouring polymer +
solvent in petri dish
Die cutter
Gloves
Balance
C
D
Polymer thick
film 1.5~2.0 mm
B
Solvent and
polymer
E
48 hr drying to
evaporate solvent
F
Pellets <strong>of</strong>
different
diameters
Filler
Stop watch
Figure 4.9: Schematic representation <strong>of</strong> processing pellets by wet method.
2 ScCO 2 Foaming Process
Foaming <strong>of</strong> polymers and composites was processed in two different laboratories: <strong>the</strong>
"Laboratoire de Génie Chimique" and <strong>the</strong> "Laboratoire d’Automatisme et d’Analyse des Systèmes" <strong>of</strong>
Toulouse.
2.1 SEPAREX TM SF200 scCO 2 Pilot Plant
2.1.1 Experimental Device
Runs were first carried out in a SEPAREX SF200 pilot (Separex Company, Nancy, France)
represented in Figure 4.10 and Figure 4.11. Briefly, this apparatus is composed <strong>of</strong> a 200 mL extractor
chamber, which is used for foaming process in which CO 2 is being injected. Basically this is a setup for
extraction purpose. Indeed a metallic vessel was placed inside <strong>the</strong> extractor, in order to reduce its volume
from 200 to 20 mL. Fur<strong>the</strong>r a Teflon roll is also inserted in <strong>the</strong> metallic roll so that pellets may not fall
during <strong>the</strong> foaming process. A cascade <strong>of</strong> three 15 mL cyclonic separators is connected to <strong>the</strong> mixing
chamber outlet. Pressure in <strong>the</strong> mixing chamber is adjusted by a backpressure regulator and, in each
separator, by depressurization valves. Sub-cooled liquid CO 2 is pumped by a volumetric membrane pump
(Milton Roy, maximum 5 kg/h), <strong>the</strong>n heated until <strong>the</strong> desired temperature and continuously introduced
into <strong>the</strong> mixing chamber. Experiments can be carried out in open-loop or closed-loop configuration, in
which case, after condensation, CO 2 is recycled to <strong>the</strong> pump. Temperatures and pressures are controlled in
each unit <strong>of</strong> <strong>the</strong> pilot, pressure being limited to 300 bars and temperature around 333 K. Before starting an
experiment, <strong>the</strong> pilot is filled with CO 2 at bottle pressure (about 5.5 MPa) and air is flashed out.
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