Introduction
Experimental section
Materials
Preparation of rubber compounds
Samples | Rubber-phr silica | SBR | EPDM | Si 69 | Sunpar 150 | Stearic acid | ZnO | TMQ | PEG |
---|---|---|---|---|---|---|---|---|---|
1. | SBR-0 phr | 137.5 | – | – | – | 2 | 4 | 1.25 | – |
2. | SBR-5 phr | 137.5 | – | 0.5 | – | 2 | 4 | 1.25 | – |
3. | SBR-10 phr | 137.5 | – | 1 | – | 2 | 4 | 1.25 | – |
4. | SBR-20 phr | 137.5 | – | 2 | – | 2 | 4 | 1.25 | – |
5. | SBR-50 phr | 137.5 | – | 5 | – | 2 | 4 | 1.25 | – |
6. | EPDM-0 phr | – | 100 | – | – | 1 | – | 1.25 | – |
7. | EPDM-5 phr | – | 100 | 0.5 | 2 | 1 | – | 1.25 | 2 |
8. | EPDM-10 phr | – | 100 | 1 | 4 | 1 | – | 1.25 | 2 |
9. | EPDM-20 phr | – | 100 | 2 | 8 | 1 | – | 1.25 | 2 |
10. | EPDM-50 phr | – | 100 | 5 | 20 | 1 | – | 1.25 | 2 |
11. | 50/50 SBR/EPDM-20 phr | 68.75 | 50 | 2 | 5 | 1.5 | 2 | 1.25 | 1 |
12. | 50/50 SBR/EPDM-50 phr | 68.75 | 50 | 5 | 10 | 1.5 | 2 | 1.25 | 1 |
13. | 30/70 SBR/EPDM-20 phr | 41.25 | 70 | 2 | 5 | 1.5 | 2 | 1.25 | 1.4 |
14. | 70/30 SBR/EPDM-20 phr | 96.25 | 30 | 2 | 5 | 1.5 | 2 | 1.25 | 0.6 |
Mixing of the components
Time (min sec) | Action |
---|---|
0.00 | Open ram, add rubber |
0.20 | Close ram |
1.20 | Add ½ silica, ½ silane, ½ ZnO, ½ stearic acid, ½ TMQ |
2.20 | Close ram |
3.20 | Open ram, add ½ silica, ½ silane, ½ ZnO, ½ stearic acid, ½ TMQ |
4.20 | Close ram |
7.20 | Open ram, sweep and dump |
Step 2
| |
0.00 | Load compound |
5.00 | Dump |
RPA test
Tensile measurements
AFM
Results and discussion
Tensile measurements
Elastomers | Silica content (phr) | Average E-modulus (MPa) |
---|---|---|
SBR | 0 | 0.5 |
SBR | 20 | 0.8 |
SBR | 50 | 4.9 |
EPDM | 0 | 1.4 |
EPDM | 10 | 1.9 |
EPDM | 20 | 2.7 |
EPDM | 50 | 4.4 |
SBR/EPDM (50/50 blend) | 20 | 3.5 |
SBR/EPDM (50/50 blend) | 50 | 5.5 |