Thermal degradation and flame retardance in copolymers of methyl methacrylate with diethyl(methacryloyloxymethyl)phosphonate

摘要: Methyl methacrylate (MMA) has been free radically copolymerized, both in bulk and solution, with diethyl(methacryloyloxymethyl)phosphonate (DEMMP), to give polymers which are significantly flame retarded when compared PMMA, as indicated by the results of limiting oxygen index (LOI) measurements, UL 94 tests, cone calorimetric experiments. The physical mechanical properties copolymers similar those except that slightly crosslinked, better than PMMA a extent some phosphate phosphonate additives. Examination gaseous products pyrolysis combustion, chars produced on burning, show retardation occurs condensed-phase vapour-phase mechanism. mechanism is shown involve generation phosphorus acid species followed reaction these MMA units giving rise methacrylic units. subsequently form anhydride links, probably impede depolymerization remaining sequences, resulting evolution less (the major fuel MMA-based burn). By undergoing decarboxylation, leading interchain cyclisation and, eventually, aromaticisation, also principal precursors char.