Polymerisation Processes Polymerisation Processes Polyethylene ...

Tailoring of mwd and comonomer distribution
:
• new property combinations
different approaches possible:
• multistage process
• reactors with different reaction zones
• multisite - catalysts
%
Reduced
impact
strength.
Migration,
taste.
Smoke
and odour
during
extrusion
Processability,
stiffness
Matrix
Mechanical
strength
Conventional
ESCR and creep resistance
Melt
strength
during
extrusion
Molecular weight (= polymer chain length)
Dr. Klaus-Dieter Hungenberg, BASF AG Ludwigshafen Vorlesung Polymerisationstechnik, Universität Paderborn, WS 07/08 Polymer processes
Bimodal
Controlling mmd by different methods
Aternative processes for
bimodal PP
Dr. Klaus-Dieter Hungenberg, BASF AG Ludwigshafen Vorlesung Polymerisationstechnik, Universität Paderborn, WS 07/08 Polymer processes
M
H 2
H 2
t
33
35
Melt flow dependent in mwd
normierte Viskosität η/η o
10 0
-1
10
-2
10
-3
10
melt flow behaviour of different HDPE at 190°C
rel. Häufigkeit
HDPE 3
HDPE 2
HDPE 1
Molmasse
-4
10
-5
10
-3
10
-1
10
Scherrate γ / s
1
10
3
10
-1
Dr. Klaus-Dieter Hungenberg, BASF AG Ludwigshafen Vorlesung Polymerisationstechnik, Universität Paderborn, WS 07/08 Polymer processes
Weight %
Controlling mmd by different methods
V
M i
Ti
Dr. Klaus-Dieter Hungenberg, BASF AG Ludwigshafen Vorlesung Polymerisationstechnik, Universität Paderborn, WS 07/08 Polymer processes
V
V
V
Ti
Ti
Ti
34
36