Side-Chain-Type High Dielectric-Constant Dipolar Polyimides with Temperature Resistance

Area of Science:

• Materials Science
• Polymer Chemistry
• Dielectric Materials

Background:

• Polyimides (PI) are crucial for electronics due to excellent dielectric and thermal properties.
• Current limitations include a narrow dielectric constant range and difficulty achieving high values.
• Advanced dielectric materials are needed for high-temperature electronic applications.

Purpose of the Study:

• To design and synthesize novel polyimides with improved dielectric and thermal properties.
• To investigate the effect of a new diamine monomer (BSBPA) on polyimide performance.
• To explore structure-property relationships by varying dianhydride components.

Main Methods:

• Synthesis of a novel diamine monomer, 2,2'-bis((methylsulfonyl)methyl)-[1,1'-biphenyl]-4,4'-diamine (BSBPA).
• Polymerization of BSBPA with various dianhydrides to create new polyimide (PI) films.
• Characterization of thermal properties (T5%d, Tg) and dielectric properties (dielectric constant, energy density, efficiency).

Main Results:

• The synthesized PI-BSBPA films demonstrated high thermal stability (e.g., T5%d of 377°C, Tg of 358°C).
• The DSDA-BSBPA film achieved a dielectric constant of 6.95 at 1 kHz.
• High discharged energy density (5.25 J cm⁻³) and charge-discharge efficiency (90%) were obtained.

Conclusions:

• The novel BSBPA monomer effectively enhances dielectric and thermal properties of polyimides.
• Collaborative main-chain and side-chain engineering is key to achieving high-temperature tolerance and dielectric performance.
• These advanced polyimides show promise for high-performance electronic applications.