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采用裂解气相色谱-质谱技术研究了聚醚酰亚胺(PEI)在550℃、650℃和750℃裂解温度下的热分解行为。随着裂解温度上升,裂解产物明显增加。在750℃时聚合物分子链断裂完全,共鉴别到25种碎片组分。PEI热分解的碎片中叔丁基苯酚、叔丁基甲基苯酚、苯酚、苯胺、氰苯、2-苯基-1H-异吲哚-1,3(2H)-二酮等5种裂解产物最重要,因此可以依据这几种化合物定性鉴别聚醚酰亚胺。依据热分解产物的数量以及结构推断降解机理为:裂解首先从醚键开始,其次是酰胺基团中的C—N键,然后再经过一系列消除反应、成环反应、重排反应等形成多种裂解碎片。
The pyrolysis behavior of polyetherimide (PEI) was investigated by pyrolysis gas chromatography-mass spectrometry at 550 ℃, 650 ℃ and 750 ℃. As the pyrolysis temperature increases, the lysate increases significantly. At 750 ℃, the polymer chains were completely broken, and 25 kinds of debris components were identified. The pyrolysis products of pyrolysis products such as tert-butylphenol, t-butylmethylphenol, phenol, aniline, cyanobenzene and 2-phenyl-1H-isoindole-1,3 (2H) Therefore, polyetherimides can be identified qualitatively based on these compounds. According to the quantity and structure of thermal decomposition products, the degradation mechanism is deduced as follows: the cleavage begins with the ether bond, followed by the C-N bond in the amide group, and then undergoes a series of elimination reactions, cyclization reactions and rearrangement reactions Cracking fragments.