| Autor: |
Zhang, Yi-fei, Liu, Jian-zhong, Li, Jian, Wang, Chen-yi, Ren, Qiang |
| Předmět: |
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| Zdroj: |
Polymer Bulletin; Nov2022, Vol. 79 Issue 11, p10295-10311, 17p |
| Abstrakt: |
Curing agent microcapsules with aqueous polyurethane as the shell and imidazole derivatives as the core were synthesized by interfacial reaction. Differential scanning calorimetry and thermo-gravimetric analysis were used to investigate the factors which affected the curing performance and storage stability for microcapsules. Results showed that the imidazole-derivative curing agent microcapsules with different structures of water-based polyurethane as the shell material were successfully synthesized. The microcapsules showed a round-like shape with relatively smooth surface and had a particle size between 100 and 200 nm. The encapsulating efficiency of imidazole derivatives in the microcapsule can reach 80%. The storage stabilities of the microcapsules were investigated both under ambient conditions and under 60 °C accelerated conditions. The NCO/OH ratio was found to have a great impact on the storage stability of microcapsules. When the NCO/OH ratio was 5:1, PU-shelled curing agent microcapsules containing 21.7% imidazole derivative were fabricated. The onset curing temperature of this microcapsule was 141 °C, and the maximum curing temperature was 150 °C when it was mixed with epoxy resin at the ratio of 5:1. After being mixed with epoxy resin, the curing agent microcapsule showed the storage stability of over 30 days under room temperature conditions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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