Highly Durable and Tough Liquid Crystal Elastomers

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Liquid crystal elastomers (LCEs) possess unique anisotropic and actuation properties.
• Thermally actuatable LCEs require robust mechanical durability for reliable performance under thermomechanical cycling.
• LCEs exhibit brittleness at elevated temperatures, limiting their high-temperature applications.

Purpose of the Study:

• To enhance the high-temperature fracture and fatigue properties of LCEs.
• To develop durable LCE-based actuators for demanding applications.
• To investigate the use of interpenetrating polymer networks for LCE reinforcement.

Main Methods:

• Designing interpenetrating polymer networks (IPNs) using a secondary polyurethane network.
• Tuning the composition of polyurethane networks to optimize mechanical properties.
• Evaluating the fracture toughness and fatigue resistance of the modified LCEs at high temperatures.

Main Results:

• Significant enhancement in high-temperature fracture and fatigue properties of LCEs was achieved.
• The actuation properties of the LCEs were successfully retained after modification.
• The IPN strategy effectively mitigated high-temperature brittleness in LCEs.

Conclusions:

• Interpenetrating polymer networks with polyurethane offer a viable strategy to improve the thermomechanical durability of LCEs.
• This approach enables the fabrication of robust LCE-based actuators capable of withstanding high temperatures and cyclic loading.
• The findings pave the way for advanced applications requiring durable soft actuators.