Kinetics Prediction of Pot Life
5
The most important application of kinetics in thermal analysis is to predict reaction behavior under conditions in which it is practically impossible to make measurements, for example for very short or very long reaction times. Pot life is an important parameter that related to the thermal stability of mixed resin system, which provides information for processing and production of materials. Kinetics prediction is an efficient method to get the information about stability of materials at use (ambient) temperature. Reaction injection molding: large component/part Adhesives Example of Application Significance of the Project Prediction of Pot life of Resin System
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Transcript of Kinetics Prediction of Pot Life
The most important application of kinetics in thermal analysis is to
predict reaction behavior under conditions in which it is practically
impossible to make measurements, for example for very short or very
long reaction times.
Pot life is an important parameter that related to the thermal stability of
mixed resin system, which provides information for processing and
production of materials. Kinetics prediction is an efficient method to get
the information about stability of materials at use (ambient)
temperature.
Reaction injection molding: large component/part
Adhesives
Example of Application
Significance of the Project
Prediction of Pot life of Resin System
Methods
Applicable to reaction that can
be described by the Arrhenius
equation and the general rate
law..
2ln .
m m
Econst
T RT
0
ln(1 )
* ( )
tE
A EXPRT
Assumption: the extent of the
reaction at the peak exotherm
is constant and independent
of heating rate.
Experiment
Differential Scanning Calorimetry (DSC)
Kinetic Analysis
Kissinger method
0 20 40 60 80
0
1
2
3
4
5
ex
o
Time /min
240oC
He
at
Flo
w /
W g
-1
0 10 20 30 40
0
1
2
3
4
5
ex
o250oC
Time /min
He
at
Flo
w /
W g
-1
-25 0 25 50 75 100 125
0
1
2
3
4
5
ex
o
Time /min
He
at
Flo
w /
W g
-1
260oC
Isothermal Kinetic Measurements
The samples are not stable for isothermal
experiments.
How about dynamic
experiment?
Maximum of heat evolution occurs at time: 0, it follows nth order kinetics.
The dynamic method should work.
B
A
Samples B is more thermally
stable.
Sample A has lower stability.
150 200 250 300 350 400
0
1
2
10oC/min
13oC/min
7oC/min
4oC/min
Temp /oC
He
at
Flo
w /
W g
-1
DSC curves for sample B at
different heating rate.
Dynamic Kinetic Measurements
Pot Life of Anonymous
Resin System
0 10 20 30 40 50
1
10
100
tim
e t
o 5
% (
da
ys
)
Temperature ( oC)
Summary
Kinetic analysis can be applied in kinetics prediction.
We can use the values A and E to easily obtain time to
any conversion at any temperature of interest.
