Table 1.
The impact of silane coupling agents on fracture toughness and healing efficiency of the SHDCs and control composites
| wt % of microcapsules |
Material encapsulated |
Silane Coupling agent |
Broken micro-capsules |
KCini [MPa·m1/2] |
KCheal [MPa·m1/2] |
Healing efficiency [%] |
|
|---|---|---|---|---|---|---|---|
| % of micro- capsules |
wt% of composites |
||||||
| 0 % | No | no | -- | 0 | 0.92 ± 0.02 | -- | -- |
| 2.5 % | Water | MA-silane | 72 | 1.8 | 0.91 ± 0.07 | 0.07 ± 0.05 | 7.0 ± 6.0 |
| 2.5 % | HL | MA-silane | 72 | 1.8 | 0.90 ± 0.04 | 0.08 ± 0.02 | 9.1 ± 2.1 |
| 5 % | Water | MA-silane | 72 | 3.6 | 0.95 ± 0.04 | 0.11 ± 0.04 | 11.6 ± 3.4 |
| 5 % | HL | MA-silane | 72 | 3.6 | 0.91 ± 0.03 | 0.22 ± 0.03 | 24.2 ± 3.8 |
| 25 % | Water | MA-silane | 72 | 18.0 | 0.56 ± 0.07 | 0.14 ± 0.03 | 24.3 ± 2.0 |
| 25 % | HL | MA-silane | 72 | 18.0 | 0.57 ± 0.04 | 0.04 ± 0.01 | 6.8 ± 1.6 |
| 5 % | Water | OH-silane | 17 | 0.9 | 0.84 ± 0.07 | -- | -- |
| 5 % | HL | OH-silane | 17 | 0.9 | 0.83 ± 0.03 | -- | -- |
| 25 % | Water | OH-silane | 17 | 4.3 | 0.64 ± 0.10 | 0.13 ± 0.02 | 21.0 ± 3.0 |
| 25 % | HL | OH-silane | 17 | 4.3 | 0.75 ± 0.06 | 0.12 ± 0.04 | 16.0 ± 6.0 |