Hexamethylenediammonium dibromide is primarily used in the field of organic synthesis as a phase-transfer catalyst. It facilitates the transfer of reactants between immiscible phases, enhancing reaction rates and efficiency. This compound is also employed in the preparation of polymers, particularly in the synthesis of polyamides, where it acts as a key intermediate. Additionally, it finds application in the production of corrosion inhibitors, which are used to protect metal surfaces in various industrial processes. Its role in these applications is crucial for improving the performance and durability of materials.