Ignition temperatures and pyrolysis of a flame-retardant methyl methacrylate copolymer containing diethyl(methacryloyloxymethyl)-phosphonate units

The ignition and pyrolysis of some copolymers of methyl methacrylate (MMA) with diethyl(methacryloyloxymethyl)phosphonate (DEMMP) have been studied by a simple tube furnace and by isothermal and non-isothermal TGA. The result s indicate that copolymers containing DEMMP thermally degrade, under both a ir and nitrogen, by a mechanism which is more complex than that (simple dep olymerization) for poly(methyl methacrylate) (PMMA). The copolymers contain ing 10 mol% or more of DEMMP are inherently flame retardant in that they fa il to autoignite at 480 degreesC and take longer to autoignite at 490 degre esC than PMMA or MMA-DEMMP copolymers containing only 5 mol% DEMMP. The for mation of a carbonaceous residue or char on combustion of the MMA-DEMMP cop olymers suggests that flame retardance is due mainly to reactions in the co ndensed phase. (C) 2000 Society of Chemical Industry.