Cis-2,3-Norbornanedicarboxylic anhydride is a bicyclic aliphatic anhydride derived from norbornane. It is a white to off-white crystalline solid with a molecular formula of C9H10O3. This compound is characterized by its rigid, fused-ring structure, which imparts unique properties to the materials derived from it. The primary and most significant application of cis-2,3-norbornanedicarboxylic anhydride is as a curing agent or hardener for epoxy resins. When reacted with epoxy resins, it forms highly cross-linked, thermosetting polymers. The resulting cured materials exhibit excellent thermal stability, high glass transition temperatures (Tg), good mechanical strength, and low dielectric constants. These properties make it particularly valuable in advanced composite materials, electronic encapsulants, and high-performance coatings for the aerospace and microelectronics industries. Due to its rigid backbone, it is often used to modify and enhance the performance of standard epoxy-anhydride systems, contributing to improved heat resistance and dimensional stability. It is also investigated as a monomer or building block for synthesizing specialty polyimides and other high-temperature polymers.