The flame-retardant material - 1. Studies on thermal characteristics and flame retardance behavior of phosphorus-containing copolymer of methyl methacrylate with 2-methacryloxyethyl phenyl phosphate

2-Methacryloxyethyl phenyl phosphate/methyl methacrylate (MEPP/MMA) copolymers were synthesized by the bulk polymerization of MMA in the presence of various amounts of MEPP. MEPP was prepared by the esterification of phenyl dichlorophosphate with 2-hydroxyethyl methacrylate, followed by hydrolysis. Structural and compositional details of MEPP were obtained by Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance, ¹³C nuclear magnetic resonance, ³¹P nuclear magnetic resonance, and mass spectrometer, as well as by elemental analysis. The monomer reactivity ratios of MEPP/MMA system were calculated by the methods of Fineman-Ross, Kelen-Tüdös, and Joshi-Joshi. The thermal degradation temperature of the MEPP/MMA copolymers was considerably enhanced by only a slight decrease in T_g, as determined by differential scanning calorimetry and thermogravimetric analysis experiments. The fire-retardant properties of MEPP/MMA copolymers were also studied by LOI and UL-94 tests, indicating that an MEPP/MMA copolymer with only 2.17 wt% phosphorus can effectively inhibit burning.