Glycidyl Methacrylate (GMA)

GMA-functional acrylic powder coatings cure via reaction of the epoxide group with solid diacid hardeners, most commonly dodecanedioic acid (DDDA). The GMA-acrylic resin is synthesized by free-radical copolymerization of GMA with methyl methacrylate, butyl acrylate, and styrene at 8-15% GMA content by weight. Upon melting and mixing in the extruder, the epoxide ring-opens with the carboxyl group of DDDA at stoichiometry, yielding a hydroxy-ester crosslink. This chemistry delivers excellent UV durability and low yellowing vs. TGIC, making it the preferred cure system for outdoor architectural and automotive exterior powder coatings under AAMA 2605 and Qualicoat Class 2 specifications.