Thermal decomposition of bisphenol A-based polyetherurethanes blown with pentane Part Ⅱ—Influence of the novel NaH_2PO_4/NaHSO_4 flame retardant system

摘要

The thermal degradation process of ethoxylated bisphenol A (BPA) and oxyalkylenated 2,6-toluylenediamine-based polyurethane (PU) foams blown with pentane and flame retarded by novel NaH_2PO_4 and NaHSO_4 intumescent system (5:3, w/w) was studied by thermogravimetry coupled with mass spectrometry (TG-MS), thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR), pyrolysis-gas chromatography coupled with mass spectrometry (Py/GC-MS) and diffuse reflectance Fourier transform spectroscopy (DRIFTS) methods. It has been found that NaH_2PO_4/NaHSO_4 system is active both at the initiation stage of PU decomposition as well as it catalyses cross-linking reactions that lead to enhanced char formation during degradation; both effects contribute to the overall flame retardation effect.