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Updated: Aug 5, 2026
11:17
Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction
Published on: January 19, 2016
Intrinsically Flame-Retardant Liquid Crystal Elastomers With Flame-Triggered Actuation Enabled by Main-Chain P─C Bond
Shimin Shao1, Yujian Liu1, Yifeng Xu1
1School of Chemistry and Chemical Engineering, State Key Laboratory of Digital Medical Engineering, Southeast University, Nanjing, Jiangsu Province, China.
Angewandte Chemie (International Ed. in English)
|July 27, 2026
Summary
New liquid crystal elastomers (LCEs) offer intrinsic flame retardancy without compromising reversible actuation. These organophosphorus LCEs are suitable for demanding applications, enabling flame-triggered responses.
Area of Science:
- Materials Science
- Polymer Chemistry
- Soft Robotics
Background:
- Liquid crystal elastomers (LCEs) are effective soft actuators but face challenges integrating fire safety with reversible actuation.
- Current flame-retardant methods can impair LCE performance, and existing phosphorus-based liquid crystal polymers (LCPs) are typically rigid and unsuitable for actuation.
Purpose of the Study:
- To develop intrinsically flame-retardant LCEs that maintain reversible actuation capabilities.
- To explore a novel polymerization strategy for creating organophosphorus LCPs and LCEs.
Main Methods:
- A radical-mediated P─H/ene step-growth polymerization strategy was employed using hypophosphorous acid and diene-terminated mesogenic monomers.
- This method forms main-chain P─C bonds, avoiding rigid aromatic phosphorus units.
Main Results:
- The developed organophosphorus LCEs exhibit reduced phase-transition temperatures and high phosphorus content (up to 6.8 wt.%).
- These LCEs retain thermotropic liquid-crystalline behavior, demonstrate reversible thermoactuation, and possess significant flame retardancy (reduced heat release, self-extinguishing).
- Flame-triggered actuation was observed in 0.4 s, with preserved structural integrity and function post-exposure.
Conclusions:
- A practical molecular design for intrinsically flame-retardant LCE actuators was established.
- These LCEs are suitable for use in thermally harsh environments, overcoming the fire safety limitations of current soft actuators.
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