Introduction: Bisphenol A Dianhydride (BPADA) , chemically known as 2,2-Bis(4-(3,4-dicarboxyphenoxy)phenyl)propane dianhydride, is a high-performance aromatic dianhydride monomer with the CAS number 38103-06-9. It is also widely referred to as 4,4'-(4,4'-Isopropylidenediphenoxy)bis(phthalic anhydride) and is commonly known by the trade name ULTEM Dianhydride. BPADA is a key building block in synthesis of advanced polymeric materials, particularly polyimides and PEIs. Its unique molecular structure—featuring a central bisphenol A core linked to two phthalic anhydride moieties via flexible ether bridges —imparts exceptional properties to its derived polymers, making it indispensable in high-technology applications ranging from aerospace to 5G electronics. Synthesis: The industrial-scale synthesis of BPADA can be achieved through a multi-step process. A common synthetic route involves the reaction of the disodium salt of bisphenol A with a halogen-substituted phthalic anhydride. An alternative method starts from N-alkyl phthalimide and proceeds through nitration, purification, bisimide formation, hydrolysis, acidification, and dehydration to yield the final dianhydride product.
Key Applications: 1. Polyimide & Polyetherimide Synthesis BPADA serves as a primary monomer in the production of polyimides and polyetherimides (PEIs)—advanced engineering thermoplastics renowned for their exceptional thermal stability, mechanical integrity, and chemical resistance. Unlike rigid dianhydrides such as PMDA or BTDA, which often yield insoluble and difficult-to-process polyimides, BPADA's flexible ether and isopropylidene linkages enhance polymer solubility in organic solvents, enabling scalable coating and prepreg manufacturing. Polyetherimides derived from BPADA are melt-processable—they retain the outstanding performance characteristics of traditional polyimides while offering the processing advantages of conventional thermoplastics at a more economical cost. 2. Flexible Electronics & 5G Applications BPADA has emerged as a critical material for next-generation flexible electronics. Polyimide films synthesized from BPADA exhibit high optical transparency (due to their non-fully conjugated structure), equibiaxial stretchability, and a high glass transition temperature (Tg = 207 °C)—properties that make them ideal for flexible display substrates. SABIC's SD1100P high-purity BPADA powder, introduced in 2021, is specifically designed for polyimide film formulations used in 5G flexible printed circuit boards (PCBs), colorless displays, and other flexible electronics. Key performance advantages include: --Low dielectric constant (2.8–2.9) and low dissipation factor for high-frequency signal transmission --Reduced water absorption, enhancing reliability and dimensional stability --Improved metal adhesion for copper-clad laminates and coverlays --Lower color for colorless display applications 3. Advanced Separation Membranes BPADA-based polyimides demonstrate promising performance in gas separation applications, achieving CO₂/CH₄ permselectivity of approximately 37.2 for natural gas sweetening. The polymers are also used to fabricate ion-transporting membranes for fuel cell applications. 4. Aerogels & Specialty Materials BPADA is utilized in the fabrication of hydrophobic polyimide aerogels exhibiting superhydrophobicity (lotus effect), expanding its utility into lightweight, high-performance insulation materials. 5. Epoxy Curing Agent Beyond polyimide synthesis, BPADA (and its related BISDA grades) can function as an anhydride curing agent in epoxy systems, offering improved thermal performance, extended pot life, better chemical resistance, lower dielectric properties, and reduced moisture absorption compared to conventional curing agents Conclusion: BPADA (CAS 38103-06-9) stands as a cornerstone monomer in the field of high-performance polymers. Its unique combination of a rigid bisphenol A core with flexible ether linkages enables the production of polyimides and polyetherimides that balance exceptional thermal and mechanical properties with superior processability. From flexible 5G electronics and transparent displays to aerospace composites and gas separation membranes, BPADA continues to enable technological innovation across a broad spectrum of advanced applications. Product manager: Joy Wu CONTACT/Email address: Joy@coreychem.com
