3,3′,4,4′-Benzophenonetetracarboxylic dianhydride (BTDA)

Basic Information of BTDA

Product Name	3,3',4,4'-Benzophenonetetracarboxylic dianhydride
Abbreviation	BTDA
CAS Number	2421-28-5
Product Type	Benzophenone-type aromatic dianhydride monomer
Molecular Formula	C17H6O7
Molecular Weight	322.23 g/mol
Appearance	Off-white to white powder
Purity	≥ 98%
Melting Point	≥ 224°C; available batch result 224.1–226.7°C
Metal Testing	Single metal ≤ 1 ppm; available batch result approved
Main Application	Heat-resistant, electronic-grade and specialty polyimide synthesis
Package	1 kg/bottle, 20 kg/drum, or customized packaging
Documents	COA, SDS and TDS available upon request
Molecular Structure

Typical Specification of BTDA

The above data is based on an available batch COA for BTDA CAS 2421-28-5. Final specifications, batch data and documentation should be confirmed by the latest COA before order confirmation.

Key Features in Polyimide Design

• Benzophenone-type aromatic dianhydride structure, relevant to  polyimide dianhydride monomers  used in heat-resistant PI systems.

• Rigid aromatic backbone may support thermal stability, mechanical strength and dimensional  control depending on the paired diamine and formulation.

• Benzophenone carbonyl structure can influence molecular packing and processability in selected  polyimide systems.

• BTDA-based PI systems are commonly discussed in  electronics and microelectronics polyimide applications  where insulation, thermal endurance and mechanical properties are important.

• The final material properties depend on dianhydride purity, diamine selection, solvent system,  imidization conditions and polymer processing method.

Pairing BTDA with Diamine Monomers

In polyimide synthesis, BTDA may be evaluated with selected polyimide diamine monomers supply portfolio to design thermally stable, mechanically robust and specialty polyimide systems. Rigid aromatic diamines may support heat resistance and dimensional stability, while ether-containing diamines may help improve processability and film-forming behavior.

Fluorinated diamines such as TFMB / TFDB CAS 341-58-2 can be considered when the formulation requires additional control of dielectric behavior or optical properties, while ether-containing diamines such as BAPP CAS 13080-86-9 may support processability and flexibility in selected PI systems.

Application Context of BTDA in Polyimide Systems

BTDA is typically used as a structural dianhydride monomer rather than a finished application material. It is commonly considered in heat-resistant, electronic-grade and specialty polyimide material development, where thermal stability, mechanical strength and processability are important design factors.

• Electronics and microelectronics polyimide applications  – insulation, dielectric and thermally stable polymer material design.

• High-temperature aerospace polyimide insulation systems  – heat-resistant insulation and structural polymer environments.

• Specialty functional polyimide development  – aromatic dianhydride selection for advanced polymer research.

• Heat-resistant films, varnishes and coatings – BTDA-based polyimides may be considered  where thermal endurance and mechanical integrity need to be balanced.

Related Polyimide Monomer Supply Guides

For a broader technical overview of both diamine and dianhydride monomer families, please review Polyimide Monomers: Diamines and Dianhydrides.

Related Polyimide Monomers

• BPDA CAS 2420-87-3  – rigid aromatic dianhydride for low-CTE and high-temperature polyimide films.

• ODPA CAS 1823-59-2  – ether-containing dianhydride for processable and flexible PI systems.

• BAPP CAS 13080-86-9  – ether-containing aromatic diamine for processable and heat-resistant polyimide systems.

COA, SDS and Technical Documentation

Please share the required purity, target specification, quantity, destination country or port, preferred packaging method and required documents so we can review availability, documentation support and export packing options.