Flame retardancy of a novel high transparent poly(methyl methacrylate) modified with phosphorus-containing compound

It is challenge for improving the flame retardancy of poly(methyl methacrylate) (PMMA), and meanwhile keeping its inherent high transparency. In this paper, a phosphorus containing monomer synthesized by our group is introduced into PMMA via radical copolymerization to prepare a flame retardant and transparent modified PMMA. The structure and properties of the obtained copolymer is characterized. With 15% mol of the phosphorus containing monomer involved, the copolymer exhibits a comparable transparency with PMMA, and its limit oxygen index (LOI) reaches 27.5% and passes UL-94 V-0. The flame retardance mechanism of the copolymer is further analyzed by thermogravimetric analysis (TGA), cone calorimetry, scanning electron microscope (SEM) and Fourier transform infrared light spectrograph (FT-IR). [Display omitted] •A new phosphorus-containing compound contains both aliphatic and aromatic phosphonate is synthesized•Flame retardant PMMA with high transparency is achieved by the copolymerization•The flame retardant mechanism is discussed based on gas phase and condensed phase.