| Epoxy resins are one of the most important types of reactive glues. By changing the curing agents and/or conditions of curing, the rate of reaction is influenced. |
| For technical applications, the real curing behavior for certain conditions is a point of interest. Therefore, the kinetics of the curing reaction is often investigated on the basis of commercial products. |
| It is well known that only on the basis of several measurements, performed at different heating rates and/or different temperatures, the predictions exhibit a sufficient level of confidence. Therefore in this example 3 dynamic and 3 isothermal measurements are combined. |
| |
| Measurements |
| Instrument: |
NETZSCH DSC 204 Phoenix® |
| Heating rates of dynamic measurements/(K/min): |
0.25, 1, 5 |
| Isothermal temperatures/°C: |
137, 167, 197 |
| Sample mass /mg: |
8 .. 12 |
|
| |
| Model-free analysis |
| Model-fit |
 |
| This picture demonstrates that it is possible to describe simultaneously with a high fit quality dynamic and isothermal measurements in addition to using the same kinetic model. |
| |
| Prediction according to a user-defined temperature program |
 |
| After definition of a temperature program, including heating up, cooling down and isothermal steps the fractional reaction is calculated, using the results of kinetic analysis. |
| |
| Isothermal Prediction |
 |
| The fractional reaction - at DSC by partial area - is calculated for a set of temperatures and a certain time. |
| |
| Tabular report of the time for a given degree of reaction
(Partial Area) Maximum time: 200 min |
| |
| Partial Area/% |
Temperature/°C |
| |
120 |
130 |
140 |
150 |
160 |
170 |
180 |
190 |
| 2 |
9.1 |
5.4 |
3.3 |
2.0 |
1.3 |
0.8 |
0.5 |
0.4 |
| 5 |
21.3 |
12.7 |
7.8 |
4.9 |
3.1 |
2.0 |
1.3 |
0.9 |
| 10 |
38.3 |
23.2 |
14.4 |
9.1 |
5.9 |
3.9 |
2.6 |
1.7 |
| 20 |
65.2 |
40.2 |
25.4 |
16.3 |
10.7 |
7.1 |
4.8 |
3.3 |
| 30 |
87.2 |
54.5 |
34.8 |
22.6 |
15.0 |
10.1 |
6.9 |
4.8 |
| 40 |
107.5 |
67.8 |
43.7 |
28.6 |
19.1 |
13.0 |
8.9 |
6.2 |
| 50 |
128.1 |
81.4 |
52.8 |
34.9 |
23.5 |
16.0 |
11.1 |
7.8 |
| 60 |
151.0 |
96.6 |
63.1 |
42.0 |
28.4 |
19.5 |
13.6 |
9.7 |
| 70 |
179.4 |
115.5 |
75.9 |
50.8 |
34.6 |
23.9 |
16.8 |
12.0 |
| 80 |
|
143.0 |
94.6 |
63.8 |
43.7 |
30.4 |
21.5 |
15.4 |
| 90 |
|
197.8 |
132.0 |
89.7 |
62.0 |
43.6 |
31.1 |
22.4 |
| 95 |
|
|
181.2 |
124.0 |
86.2 |
61.0 |
43.7 |
31.8 |
| 98 |
|
|
|
190.0 |
133.0 |
94.6 |
68.3 |
49.9 |
|
Thermokinetics
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