Analysis and toxicity testing of combustion gases 2. Characterisation of combustion products from halogen-free flame-retardant duroplastic polymers for electronics

摘要

Gaseous combustion products from two new halogen-free flame-retardant polymers for electronic engineering were characterised using analytical and toxicological methods. These duroplastic materials, developed by Siemens, are based on novolak-glycidyl-ether and bisphenol-A-diglycidyl-ether. They contain oxazolidinone and isocyanurate structures as well as phosphonate elements in the polymeric backbone which are responsible for their flame-retardancy. The polymeric materials were combusted in a VCI oven at 200, 400, 600 and 800℃. The combustion gases were sampled on two cartridges containing Tenax and a third, containing a molecular sieve connected in series. The ethanolic eluates of the Tenax were analysed by gas chromatography/mass spectrometry (GC/MSD) and gas chromatography/infrared spec-troscopy. This solution was also used for toxicity testing with the Microtox Test~® after appropriate dilution. The fraction of highest volatility was desorbed from the molecular sieve and analysed directly via headspace GC/MSD. The thermal reactions of the two new polymers are discussed and compared with literature data. Reaction pathways of the nitrogen containing structure elements to N-heterocyclic compounds during combustion were proposed. Some factors regarding the fate of the phosphorus during combustion were discovered. The results of the Microtox Test~® were compared with data from the combustion of polystyrene and beech-wood.