fnctId=thesis,fnctNo=31
Harnessing β-hydroxyl groups in poly (β-amino esters) toward robust and fast reprocessing covalent adaptable networks
- Link
- https://pubs.acs.org/doi/full/10.1021/acs.macromol.2c01872
- Writer
- 김시윤
- Author
- Gyuri Lee, Hyeong Yong Song, Subi Choi, Chae Bin Kim, Kyu Hyun, Suk-kyun Ahn
- Publication matter
- Macromolecules
- Publication Date
- 2022-11-28
- Korean Abstract
- English Abstract
- Poly(β-amino esters) (PBAEs), which include tertiary amines at the β-position of ester linkages, are promising in biomaterials due to their biodegradability and pH responsiveness. Such characteristics in the molecular structure are also appealing for designing catalyst-free covalent adaptable networks (CANs), but this has rarely been explored in the literature. Herein, we synthesize a series of PBAE-based CANs by aza-Michael addition, using diacrylate monomers with and without β-hydroxyl groups, and a triamine crosslinker. By leveraging hydrogen bonding, the thermal and mechanical properties of these PBAE-based CANs are effectively tuned through the monomer composition. Owing to the numerous tertiary amines serving as internal catalysts, these CANs undergo catalyst-free network exchange through a dynamic aza-Michael reaction. Interestingly, increasing the amount of β-hydroxyl groups accelerates overall stress relaxation from the synergistic effects of transesterification (associative type) at lower temperatures and dynamic aza-Michael reaction (dissociative type) at higher temperatures. Based on these features, we successfully demonstrate the reprocessing and healing at elevated temperatures under mild pressure, as well as shape memory and shape reconfiguration. Thus, controlling the β-hydroxyl group concentration in PBAE-based CANs is a useful strategy for enhancing both the mechanical strength and reprocessing rate.
- Text
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