The primary purpose of Maleic Acid Monomethyl Ester is to serve as a versatile unsaturated monomer in various chemical applications. It reacts efficiently with epoxy groups, specifically forming monomethyl maleic esters of ESO (MESO) when combined with AMC-2 catalyst. As a member of the glycol ether group, it is integral in producing polyvinyl alcohol with enhanced water vapor resistance. Furthermore, it acts as a solvent for tiglic acid and aids in copolymerization with other monomers like citric acid and maleate or ethylene. Its role extends to functioning as an anhydride in the production of glycol ethers, aligning its utility closely with that of its relative compound, Maleic Anhydride, known for its wide-ranging applications including in unsaturated polyester resins and various synthetic agents.