Diisopropyl fumarate is primarily used as a reactive diluent in the production of unsaturated polyester resins. It helps in reducing the viscosity of the resin, making it easier to handle and process during manufacturing. This chemical is also employed in the formulation of coatings and adhesives, where it enhances the flexibility and durability of the final product. Additionally, diisopropyl fumarate finds application in the synthesis of certain pharmaceuticals, where it acts as an intermediate in the production of active pharmaceutical ingredients. Its ability to polymerize under specific conditions makes it valuable in creating specialized polymers with tailored properties.