A novel thermoplastic shape memory polymer with solid-state plasticity derived from exchangeable hydrogen bonds.

Area of Science:

• Polymer Science
• Materials Science
• Nanotechnology

Background:

• Shape memory polymers (SMPs) offer tunable properties for advanced applications.
• Developing SMPs with efficient shape recovery and plasticity is crucial for practical use.
• Existing SMPs often require catalysts or molds for permanent shape reconfiguration.

Purpose of the Study:

• To synthesize a novel thermoplastic shape memory polymer (SMP).
• To investigate the role of hydrogen bonds in creating dynamic polymer networks.
• To achieve solid-state plasticity for facile permanent shape reconfiguration without external aids.

Main Methods:

• Synthesis of a novel thermoplastic SMP by modifying trans-1,4-polybutadiene (TPB) with mono-isocyanate.
• Formation of comb-like chains with hydrogen bonds creating dynamic non-covalent polymer networks.
• Characterization of shape fixity, shape recovery, and stress relaxation properties.

Main Results:

• An optimal SMP with 30% modification exhibited 100% shape fixity and 89.57% shape recovery.
• Stress relaxation tests at 70°C showed a relaxation time of 27s, indicating rapid network rearrangement.
• The dynamic hydrogen bond network facilitated rapid topological rearrangement and solid-state plasticity.

Conclusions:

• The synthesized SMP possesses a dynamic non-covalent network enabling efficient permanent shape reconfiguration.
• The material's solid-state plasticity allows for complex shape changes without catalysts or molds.
• This SMP shows significant potential for diverse engineering applications requiring reconfigurable materials.