聚三氟氯乙烯纯氧环境热解气体产物分析

Analysis of Gaseous Product of Polychlorotrifluoroethylene Pyrolysis in Pure Oxygen Environment

使用针筒采样法采集聚三氟氯乙烯纯氧环境等温(400℃/450℃)热解气体产物,通过气相色谱-质谱联用技术和真空紫外光电离质谱技术,定性分析热解气体产物组成成分,为评估氧气系统在设计和使用过程中的安全性提供参考.结果表明:聚三氟氯乙烯纯氧热解气体产物中共检出13种气体成分,其中氟氯烷类4种,单烯类5种,小分子类4种.分析认为氟氯烷类和单烯类气体产物的生成是由于聚三氟氯乙烯在热解过程中发生碳链、碳氯键及碳氟键的无规则断裂和重新结合,而小分子类气体产物的生成是由于聚三氟氯乙烯在热解过程中发生氧化生成中间体(COF_(2)、COFCl),中间体进一步分解产生CO、CO_(2)、Cl_(2)和F_(2).

A needle sampling method was used to collect the gaseous product isothermally(400℃/450℃)pyrolyzed by polychlorotrifluoroethylene(PCTFE)in a pure oxygen environment.The composition of the gas product was qualitatively analyzed by gas chromatography-mass spectrometry(GC-MS)and vacuum ultraviolet photoionization mass spectrometry(VUV-PIMS),providing reference for evaluating the safety of an oxygen system in its design and use.Results showed that 13 kinds of gas components were detected,including 4 kinds of chlorofluoroalkanes,5 kinds of monoenes and 4 kinds of micromolecule.According to the analysis,it is found that the formation of chlorofluoroalkanes and monoenes is due to the random fracture and recombination of carbon chains,carbon-chlorine bonds and carbon-fluorine bonds in the pyrolysis process of PCTFE.In comparison,the generation of micromolecules is the result of the oxidation of part of PCTFE in the pyrolysis process to produce intermediates(COF_(2) and COFCl),which are further decomposed into CO,CO_(2),Cl_(2),and F_(2).