Enhanced Interfacial and Dielectric Performance for Polyetherimide Nanocomposites through Tailoring Shell Polarities

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Polyimide (PI) and polyetherimide (PEI) are explored for dielectric energy storage.
• Current research on PI/PEI nanocomposites often overlooks the impact of diverse dianhydride-derived polar groups.

Purpose of the Study:

• To investigate the effect of various dianhydride monomers on dielectric properties.
• To fabricate novel hyperbranched polyimides grafted on barium titanate nanoparticles (HBPI@BT) and their nanocomposites with PEI.

Main Methods:

• Synthesis of HBPI@BT using different dianhydride monomers.
• Fabrication of HBPI@BT/PEI nanocomposites.
• Characterization of dielectric properties, bonding energy, breakdown strength, and dielectric loss.

Main Results:

• Hyperbranched structures improved filler-matrix compatibility and bonding energy (e.g., 797.7 kJ/mol for HBPI-S@BT/PEI).
• HBPI-S@BT/PEI achieved a dielectric energy density (Ud) of 8.38 J/cm³, 3.3 times higher than pure PEI.
• HBPI-F@BT/PEI demonstrated high breakdown strength (∼500 MV/m) and low dielectric loss (0.008).
• Dielectric constants remained stable between 25–150 °C.

Conclusions:

• Hyperbranched polyimide structures offer a promising approach for enhancing dielectric nanocomposite performance.
• These materials show potential for advanced dielectric applications, including field-effect transistors.