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Multiple/Two-Way Shape Memory Poly(urethane-urea-amide) Elastomers
Zhen Li1, Shuxiang Mei1, Lu Luo1
1School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China.
Macromolecular Rapid Communications
|October 17, 2022
Summary
New poly(urethane-urea-amide) elastomers exhibit multiple and two-way shape memory effects (M/2W-SME). These advanced polymers demonstrate excellent mechanical properties and high-temperature shape memory capabilities for demanding applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Shape memory polymers (SMPs) offer large deformation, lightweight design, and strong recovery stress.
- Multiple and two-way reversible shape memory polymers (M/2W-SMPs) are crucial for advanced applications.
- Existing SMPs often have limitations in temperature range or complexity of shape memory behavior.
Purpose of the Study:
- To synthesize and characterize novel semi-crystalline block poly(urethane-urea-amide) elastomers (PUUAs).
- To investigate the multiple and two-way reversible shape memory effects (M/2W-SME) in these PUUAs.
- To explore the potential of PUUAs for high-temperature applications and complex shape transformations.
Main Methods:
- Copolymerization of isocyanate-terminated polyurethane (OPU) and amino-terminated oligomeric polyamide-1212 (OPA).
- Characterization of mechanical properties, including tensile strength and elongation at break.
- Differential scanning calorimetry (DSC) to determine thermal transitions (crystallization/melting temperatures, glass transition temperature).
- Evaluation of multiple and two-way shape memory behaviors under varying conditions.
Main Results:
- The synthesized PUUAs exhibited excellent rigidity, flexibility, and resilience.
- cPUUA-C7-S25 demonstrated superior tensile properties (10.3 MPa strength, 360.2% elongation at break).
- All PUUAs displayed multiple and reversible two-way shape memory effects due to distinct thermal transitions.
- Physically crosslinked PUUA-C0-S25 showed dual and triple shape memory, while microchemically crosslinked cPUUA-C7-S25 exhibited quadruple shape memory.
- cPUUA-C7-S25 achieved high-temperature shape memory up to 165 °C.
Conclusions:
- The developed PUUAs possess significant M/2W-SME and high-temperature shape memory capabilities.
- The material's properties make it suitable for advanced applications requiring complex shape transformations.
- Potential applications include high-temperature sensors, actuators, and aerospace equipment.
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