4,4'-Methylenedibenzoic acid is primarily used in the synthesis of polymers and resins. It serves as a key monomer in the production of high-performance polyesters and polyamides, which are valued for their thermal stability and mechanical strength. These materials are often employed in engineering plastics, coatings, and adhesives, particularly in industries requiring durable and heat-resistant components. Additionally, it is utilized in the development of liquid crystal polymers (LCPs), which are essential in electronics for manufacturing connectors, sensors, and other precision parts. Its role in creating advanced materials makes it significant in applications ranging from automotive to aerospace industries.