Study of Pyrolysis Gaseous Products of Various Fibers-Relationship between Pyrolysis Products and Flame Retardancy

采用居里点裂解气相色谱(Py-GC)和居里点裂解气相色谱-质谱仪(Py-GC-MS)研究了棉、真丝和羊毛织物的热解过程。棉花样品的热解温度为590ﾟC，羊毛和丝绸样品的热解温度为794ﾟC。未经处理的棉花样品的Py-GC色谱图显示，纤维素热解的关键中间产物左旋葡聚糖的形成。经磷阻燃剂处理的棉花样品中左旋葡聚糖的含量较低。此外，随着处理棉样中磷含量的增加，挥发性热解产物总量减少。Py-GC分析结果与阻燃效果一致。丝绸和羊毛样品的热解产物均为氰化氢、乙腈和丙烯腈，均含氮。此外，羊毛样品还通过热解生成了含硫的硫化氢、羰基硫化物和甲硫醇。用溴或N-溴代丁二酰亚胺处理的丝绸和羊毛样品产生了含溴的溴甲烷、溴乙烷、溴苯酚和溴甲酚。热解产物样品总量随处理时间的延长而减少。综上所述，化学处理纤维的Py-GC和Py-GC-MS分析对于评价处理纤维的阻燃性能和化学改性纤维的结构分析是一种有用的工具。

Pyrolysis of cotton, silk and wool fabrics was studied by Curie-point pyrolysis-gas chromatography (Py-GC) and Curie-point pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The pyrolysis temperature for cotton samples was set 590ﾟC while that for wool and silk samples were 794ﾟC.A Py-GC chromatogram of the untreated cotton showed the formation of levoglucosan, a key intermediate in the pyrolysis of cellulose. Cotton samples treated with phosphorus flame retardants gave less levoglucosan. Moreover, the total amount of the volatile pyrolysis products decreased with increase in the phosphrus contents of the treated cotton samples. These values obtained by Py-GC were consistent with the flame retardancy attained by the treatment.Characteristic pyrolysis products from both silk and wool samples were hydrogen cyanide, acetonitrile and acrylonitrile all of which contain nitrogen. In addition to those, wool samples gave sulfur-containing hydrogen sulfide, carbonyl sulfide and methyl mercaptan by pyrolysis. Silk and wool samples treated with bromine or N-bromosuccinimide yielded bromine-containing bromomethane, bromoethane, bromophenol and bromocresol. The total amount of pyrolysis products samples decreased by the treatments. In conclusion it is demonstrated in this work that Py-GC and Py-GC-MS analyzes of chemically treated fibers are a useful tool for the evalution of flame retardancy of the treated fibers and the structural analysis of the chemically modified fibers.