Thermal degradation of methyl methacrylate polymers functionalized by phosphorus-containing molecules. III: Cone calorimeter experiments and investigation of residues

The flammability properties of three co-polymers of methyl methacrylate (MMA) and phosphorylated methyl methacrylate CH2C(CH3)C(O)OCHRP(O)(OC2H5)2 with RH, C6H4Br (bromophenyl) and C10H7 (naphthyl) have been investigated by cone calorimetry. The rate of heat release (RHR) peak and the CO2 production rate are significantly decreased with respect to PMMA. The chars produced during cone calorimetry tests were also investigated by scanning electron microscopy (SEM), micro-Raman and diffuse reflectance IR spectroscopy (DRIFT) and showed the presence of phosphocarbonaceous structures. Phosphorus appears to play a role as well in the gas phase as in the condensed phase. The results confirm that the studied materials have interesting fire retardant properties.