Robust Self-Healing PDMS-Based Elastomers Featuring Tunable Mechanical Properties Enabled by Dual Non-Covalent...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Developing self-healing elastomers with high mechanical performance is crucial.
• Existing self-healing polydimethylsiloxane (PDMS) elastomers often require harsh conditions or sacrifice mechanical properties.
• Traditional urea-based hydrogen bonds can crystallize, limiting stretchability and toughness.

Purpose of the Study:

• To create highly efficient self-healing PDMS elastomers with excellent mechanical properties.
• To overcome limitations of existing self-healing materials, such as harsh healing conditions and compromised mechanics.
• To explore the use of dual non-covalent interactions for enhanced material performance.

Main Methods:

• Introducing strong Zn²⁺ coordination into a thiourea hydrogen bond network.
• Synthesizing a series of polydimethylsiloxane-based elastomers (PDMS-BDTI-Zn).
• Tuning mechanical properties by varying Zn²⁺ ion content.

Main Results:

• Achieved robust and efficient self-healing elastomers with tunable mechanical properties.
• Demonstrated superior stretchability (≈6000%) and high strength (≈4.2 MPa) by adjusting Zn²⁺ content.
• Exhibited complete surface scratch healing at room temperature within 24 hours and >90% mechanical property recovery under mild conditions (60°C, 6h).
• Explored potential applications in hydrophobic coatings due to PDMS's inherent hydrophobicity.

Conclusions:

• The integration of Zn²⁺ coordination with thiourea hydrogen bonds yields advanced self-healing elastomers.
• These materials offer a promising balance of mechanical robustness, stretchability, and efficient self-healing capabilities.
• The developed elastomers show potential for applications requiring durable and self-repairing surfaces.