Liquid crystalline elastomers (LCEs) are stimuli‐responsive materials capable of undergoing large deformations. The thermomechanical response of LCEs is attributable to the coupling of polymer network properties and disruption of order between liquid crystalline mesogens. Complex deformations have been realized in LCEs by either programming the nematic director via surface‐enforced alignment or localized mechanical deformation in materials incorporating dynamic covalent chemistries. Here, the preparation of LCEs via thiol‐Michael addition reaction is reported that are amenable to surface‐enforced alignment. Afforded by the thiol‐Michael addition reaction, dynamic covalent bonds are uniquely incorporated in chemistries subject to surface‐enforce alignment. Accordingly, LCEs prepared with complex director profiles are able to be programmed and reprogrammed by (re)activating the dynamic covalent chemistry to realize distinctive shape transformations.
Covalent adaptable networks (CANs) based on the thiol–Michael (TM) linkages can be thermal and pH responsive. Here, a new vinyl‐sulfone‐based thiol–Michael crosslinker is synthesized and incorporated into acrylate‐based CANs to achieve stable materials with dynamic properties. Because of the reversible TM linkages, excellent temperature‐responsive re‐healing and malleability properties are achieved. In addition, for the first time, a photoresponsive coumarin moiety is incorporated with TM‐based CANs to introduce light‐mediated reconfigureability and postpolymerization crosslinking. Overall, these materials can be on demand dynamic in response to heat and light but can retain mechanical stability at ambient condition.
more » « less- Award ID(s):
- 1749730
- NSF-PAR ID:
- 10450209
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Macromolecular Rapid Communications
- Volume:
- 42
- Issue:
- 18
- ISSN:
- 1022-1336
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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