应用裂解气相色谱及质谱联用法研究了3种聚醚酰亚胺(PEIM′s)的裂解行为,并根据裂解产物的结构及其相对产率推断了裂解的机理。取3种PEIM样品置于石英裂解管中,分别在550 ℃,650 ℃,750 ℃条件下裂解,所得产物用气相色谱-质谱联用法分析。分析中采用DB-5毛细管色谱柱,电子轰击离子源(200 ℃,70 eV)及在m/z 29~500范围内全扫描方式,并用NIST谱库进行检索和用归一化法计算峰面积进行定量。由试验结果可知:选择在750 ℃进行裂解较好,在此条件下获得主要裂解产物存在的更明显的信息,有利于对产物进行详细分析和鉴定。

Pyrolytic behavior of 3 polyetherimides (PEIM′s) was studied by pyrolysis-gas chromatography and mass spectrometry in hyphenation (PyGC-MS), and pyrolytic mechanism of the 3 PEIM′s was deduced on the base of the structures and relative yields of the pyrolytic products. Samples of the PEIM′s were pyrolyzed in a quartz tube at 550 ℃, 650 ℃ and 750 ℃ separately and the pyrolyzates were analyzed by GC-MS using the DB-5 capillary chromatographic column, the electron ionization source (200 ℃, 70 eV) and the whole scanning mode in the range of (m/z) 29-500. The NIST spectra database was used for reference and the peak area calculated by normalization was used in quantification. As shown by the experimental results, it was better to choose 750 ℃ as the pyrolytic temperature in the analysis and identification, as more significant informations were obtained for existence of the pyrolyzates under this condition.