Laser pyrolysis/time-of-flight mass spectrometry studies pertinent to the behaviour of flame-retarded polymers in real fire situations

摘要: Abstract The Salford Laser Pyrolysis/Time-of-Flight Mass Spectrometry (LP/TOFMS) technique, which models the behaviour in so-called dark flame region behind front a polymer fire, has been applied to investigate flame-retarded polymethylmethacrylate (PMMA), rigid polyurethane foam systems and phosphorus retarded foams model urethane compound. laser pyrolysis of aluminium oxide trihydrate (ATH) PMMA produces large amount water carbon dioxide volatiles. Also, monomer evolved is reduced significantly compared that obtained from pure PMMA. implication these results real fire situation, ATH influences such manner as bring about reduction “fuel” whilst at same time adding non-combustible gases (e.g. water) region. Thus retarded. studied varied isocyanate index molecular weight polyols applied. retardance materials shown increase with increasing fraction isocyanate. experiments samples showed major volatiles were dominated by oligomers polypropylene glycol used produce foam, plus lower species appeared be significant part. An extent monomer/oligomer evolution an low species. With reference it could imagined components their breakdown products would act fuel while relatively non-flammable. equivalent making less more “inert gases” available burning zone hence improving resistance foams. retardant mechanism phosphorus, introduced percentages dimethyl methylphosphonate, also attributed via