Thermal degradation of polyether-urethanes: Part 2—Influence of the fire retardant, ammonium polyphosphate, on the thermal degradation of poly(ethylene glycol)

The principal characteristics and products of the thermal degradation of poly(ethylene glycols) (PEG), having molecular weights of 1000 and 1500, with 20% by weight of ammonium polyphosphate (APP), have been determined. In the presence of APP the mechanism of degradation of the PEG is quite different from that of pure PEG. From a single step radical chain process in the pure polymer the mechanism changes in the mixture to a three-stage series of acid catalysed reactions. Although, in each case, a complex mixture of products is obtained, 1,4-dioxane, which was not a product from pure PEG, becomes the predominating product from the mixture.