Self-Strengthening, Self-Welding, Shape Memory, and Recyclable Polybutadiene-Based Material Driven by Dual-Dynamic...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Materials

Background:

• Traditional vulcanized rubber lacks recyclability and reprocessability, contributing to environmental pollution.
• Existing recyclable rubber materials often exhibit low tensile strength, typically below 10 MPa without fillers.

Purpose of the Study:

• To develop a self-strengthening recyclable rubber material with enhanced mechanical properties.
• To overcome the strength limitations of current recyclable elastomers.
• To provide a sustainable solution for end-of-life rubber products.

Main Methods:

• Incorporation of dual-dynamic units (imine and disulfide) into a rubber network.
• Utilizing a self-strengthening mechanism involving phenylsulfur radicals generated from disulfide bonds upon heating.
• Investigating the cross-linking reactions between radicals and double/allyl bonds in the polymer backbone.

Main Results:

• Achieved a tensile strength of 19.27 MPa without fillers or additives, surpassing existing recyclable polybutadiene-based rubbers.
• Demonstrated excellent thermal reprocessability and chemical recyclability due to the stable imine units.
• Exhibited properties including malleability, shape memory, and self-welding capabilities.
• Developed a recyclable conductive composite by doping with carbon nanotubes.

Conclusions:

• The proposed self-strengthening strategy based on dual-dynamic units significantly enhances rubber strength while maintaining recyclability.
• This approach offers a promising pathway for creating high-performance, sustainable elastomers with applications in repair and assembly.
• The method is potentially generalizable to various elastomers containing double bonds, including SBR, NBR, and isoprene rubber.