Didodecyl phthalate is primarily used as a plasticizer in the production of flexible PVC products. It enhances the flexibility, durability, and workability of materials, making it suitable for applications such as cables, wires, and flooring. Additionally, it is employed in the formulation of adhesives and sealants, where it improves bonding strength and elasticity. Its stability at high temperatures makes it useful in industrial coatings and automotive components, ensuring long-lasting performance under demanding conditions.