New design strategy for reversible plasticity shape memory polymers with deformable glassy aggregates.

Area of Science:

• Materials Science
• Polymer Science
• Mechanical Engineering

Background:

• Reversible plasticity shape memory (RPSM) is a recently identified phenomenon in shape memory polymers (SMPs).
• Achieving RPSM behavior, which allows large plastic deformation and shape recovery, has been limited to a few polymer systems.
• Understanding and engineering materials with RPSM properties is crucial for advanced applications.

Purpose of the Study:

• To develop a novel SMP exhibiting RPSM properties through a new design strategy.
• To investigate the mechanism by which incorporated additives influence RPSM behavior.
• To characterize the performance of the developed SMP in terms of shape fixity, recovery, energy storage, and self-healing.

Main Methods:

• Incorporation of deformable glassy hindered phenol (AO-80) aggregates into an amorphous network of epoxidized natural rubber (ENR) cured with zinc diacrylate (ZDA).
• Characterization of the RPSM behavior, including large deformation testing (up to 300%) and thermal analysis.
• Evaluation of energy storage capacity and self-healing properties.

Main Results:

• The developed SMP demonstrated significant RPSM behavior with good shape fixity at large deformations.
• Excellent shape recovery upon heating was observed.
• The material exhibited large energy storage capacities, surpassing traditional SMPs at elevated temperatures.
• Self-healing properties were discovered and found to be linked to the RPSM behavior.

Conclusions:

• The new design strategy successfully created an SMP with robust RPSM properties.
• AO-80 aggregates effectively tune the glass transition temperature and enhance chain mobility via hydrogen bonding, enabling RPSM.
• The material shows potential for applications requiring large shape deformation, recovery, energy storage, and self-healing.