Introduction to BPDA
Chemical Name: 3,3′,4,4′-Biphenyltetracarboxylic dianhydride
Molecular Formula: C₁₆H₆O₆
Molecular Weight: 294.22
CAS Number: 2420-87-3
BPDA is an aromatic tetracarboxylic dianhydride compound, and one of the most important dianhydride monomers for synthesizing high-performance polyimides (PI).
Due to its rigid biphenyl structure and symmetric molecular backbone, BPDA significantly enhances the thermal stability, mechanical strength, and chemical resistance of polyimide materials. Consequently, it is widely used in aerospace, electronics, electrical insulation, and flexible display technologies.
1. Chemical Structure and Characteristics
BPDA consists of two benzene rings linked by a carbon–carbon bond, with carboxylic anhydride groups attached at the 3,3′,4,4′ positions.
This planar, highly conjugated, and rigid molecular architecture gives BPDA-based polyimides their exceptional properties:
Excellent thermal stability: decomposition temperature typically above 500 °C
Outstanding dimensional stability: low coefficient of thermal expansion (CTE < 20 ppm/K)
High resistance to radiation and chemicals
Superior modulus and mechanical strength, suitable for high-stress applications
These features make BPDA-derived PIs among the most heat-resistant engineering plastics available today.
2. Major Industrial Applications
(1) High-Performance Polyimide Films (PI Films)
When BPDA reacts with diamines such as p-PDA or ODA, it forms polyimide films with:
Very high glass-transition temperature (Tg > 350 °C)
Excellent dimensional stability and dielectric properties
Suitability for flexible printed circuits (FPCs), chip packaging, and display substrates (OLED, TFT-LCD)
Representative commercial products include Kapton® (BPDA-PI) and Upilex® S.
(2) Aerospace and Electronic Packaging Materials
Due to its high tensile strength and low CTE, BPDA-PI is commonly used for:
Satellite solar-cell backing films
High-temperature wire insulation
Chip encapsulation dielectric layers
Low-stress adhesive films
These materials can maintain their integrity in extreme temperature and vacuum environments.
(3) PI-Based Composites and Carbon-Fiber Prepregs
When combined with carbon fiber or glass fiber, BPDA-PI forms high-modulus, low-moisture-absorption, and heat-resistant composites used in:
Aircraft structural components
Microelectronic packaging substrates
5G antenna base materials
3. Recent Research Trends (2023–2025)
Molecular Design Optimization
Researchers are improving flexibility and processability by copolymerizing or graft-modifying BPDA with dianhydrides such as BTDA or 6FDA, achieving a better balance between rigidity and film-forming properties.
Ultrathin and Transparent PI Films
In flexible and foldable displays, BPDA-based transparent polyimides achieve low thermal expansion and high optical clarity through nanoscale molecular orientation control, making them a promising glass-replacement substrate.
Green and Sustainable Synthesis
Recent advances focus on solvent-free or low-VOC polymerization processes, and on eco-friendly solvent replacements (e.g., GBL, Cyrene) for NMP, aligning with the global movement toward sustainable polymer manufacturing.
4. Conclusion
BPDA is a high-performance aromatic dianhydride monomer that plays a vital role in the field of heat-resistant polyimides.
Its rigid molecular structure and exceptional thermal and chemical stability make BPDA-based polyimides indispensable in aerospace, flexible electronics, semiconductor packaging, and advanced film applications.
As flexible electronics, 5G communication, and renewable energy technologies continue to evolve, the industrial demand and research focus on BPDA are expected to rise steadily.
Ready to Accelerate Your Research?
For technical datasheets, sample requests, or customized catalyst solutions, contact the UIV CHEM technical support team today. Let us help you achieve breakthrough results in organic synthesis and materials innovation!