Study on the effects of flame retardants on the thermal decomposition of wood by TG-MS

The effect of three flame retardants, K2CO3, Na2SiO3 center dot 9H(2)O, and Na2B4O7 center dot 10H(2)O on the process and composition of volatile products of the thermal degradation of wood has been investigated by the thermogravimetric (TG), differential thermogravimetry (DTG), differential thermal analysis (DTA), and the synchronous thermogravimetry-mass spectrometry (TG-MS) analysis methods. The results showed that the ion current intensity and ion peak area of m/z = 18 and 44 MS signals were increased by the flame retardants but the ion peak area of m/z = 28 MS signal was decreased (except K2CO3) at the meantime. What's more, the ion current intensity and ion peak area of m/z = 60 and 68 MS signals were also decreased (except K2CO3), which mean that Na2B4O7 can significantly enhances the dehydration and inhibits the depolymerization of wood. Although K2CO3 accelerates the dehydration reaction, it cannot inhibit the depolymerization reaction effectively, so the flame retardant efficiency of K2CO3 is decreased with the higher concentration. The catalysis of dehydration reaction of Na2SiO3 is the worst one.