Tailored Molecular Fillers Enable High-Temperature Insulation and Long-Term Operating Stability in All-Organic...

Area of Science:

• Materials Science
• Polymer Science
• Electrical Engineering

Background:

• A key challenge in polymer dielectrics is controlling charge injection and transport.
• Effective electrical insulation is crucial for high-performance applications.

Purpose of the Study:

• To develop a molecular engineering strategy for enhancing the electrical insulation of polymer dielectrics.
• To investigate the use of the TU3 organic molecule as a reinforcing filler for epoxy resin (EP).

Main Methods:

• Synthesized TU3 organic molecule with a benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) backbone and zwitterionic structure.
• Incorporated TU3 as a filler into epoxy resin (EP) to create TU3/EP composites.
• Characterized the electrical properties, including breakdown strength and long-term stability, of the composites.

Main Results:

• TU3 introduction created charge traps at the molecular interface, effectively inhibiting charge injection and transport.
• A mere 0.02 wt% of TU3 increased the breakdown strength of EP composites by 30.75% at room temperature and 52.28% at 120°C.
• TU3/EP composites demonstrated excellent long-term operating stability under extreme thermal and electrical stress.

Conclusions:

• Molecular design of TU3, featuring electrostatic interactions and intermolecular charge transfer, successfully enhances electrical insulation.
• The TU3/EP composite system offers a promising solution for high-performance polymer dielectrics under demanding conditions.
• This study provides a novel approach for designing small organic molecules to improve polymer dielectric performance.