Highly Stretchable Conjugated Polymer/Elastomer Blend Films with Sandwich Structure

Area of Science:

• Materials Science
• Polymer Science
• Organic Electronics

Background:

• Physical blending of conjugated polymers and elastomers offers a route to high-performance stretchable films.
• Understanding morphology control and fracture behavior in these blends under strain is crucial but limited.

Purpose of the Study:

• To investigate the impact of a specific microstructure on the mechanical and electrical properties of conjugated polymer/elastomer blend films.
• To develop a method for enhancing the ductility and stability of stretchable electronic materials.

Main Methods:

• Fabrication of a sandwich structure using poly[(5-fluoro-2,1,3-benzothiadiazole-4,7-diyl)(4,4-dihexadecyl-4H-cyclopenta[2,1-b:3,4-b″]dithiophene-2,6-diyl)(6-fluoro-2,1,3-benzothiadiazole-4,7-diyl)(4,4-dihexadecyl-4H-cyclopenta[2,1-b:3,4-b″]dithiophene-2,6-diyl)] (PCDTFBT) and polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS).
• Characterization of the blend film's morphology and its response to mechanical stretching.
• Evaluation of crack onset strain and electrical performance degradation.

Main Results:

• A sandwich structure comprising a central mixed layer and outer PCDTFBT-rich layers was successfully constructed.
• The structure effectively dissipated strain energy through deformation and recrystallization, leading to excellent ductility.
• The blend film exhibited a large crack onset strain (>1100%) with minimized electrical degradation at high strains.

Conclusions:

• Manipulating the microstructure of conjugated polymer/elastomer blends is key to improving their electrical and mechanical properties.
• The developed sandwich structure offers a promising strategy for creating robust and high-performance stretchable electronic films.
• This approach advances the design principles for advanced functional materials in flexible electronics.