气相色谱-质谱联用研究聚乙烯在氩气中的裂变行为

Study on the pyrolysis behavior of polyethylene in argon by gas chromatography coupled with mass spectrometry

模拟电弧炉的燃烧环境,利用气相色谱-质谱联用法研究了聚乙烯在氩气气氛中不同温度、不同氩气流量下的裂变行为。结果表明:聚乙烯在氩气气氛中,在温度低于700℃时主要裂变形成链烃;在温度达到900℃时开始形成多环芳烃,温度越高,所形成的多环芳烃的种类越多,烷基化程度越高,相对浓度越大。氩气流量的变化明显影响了聚乙烯的裂变产物,实验结果验证了烯烃、二烯烃(炔烃)是多环芳烃前体化合物的假设,高温下多环芳烃生成数量和相对浓度比低温下高的主要原因是高温下聚乙烯的裂解程度增大,使得更多量烯烃、二烯烃(炔烃)形成。因此,控制烯烃、二烯烃(炔烃)等前体物的形成是减少多环芳烃排放的关键。

In a simulated burning environment of electric arc furnace, the pyrolysis behavior of poly- ethylene at different temperature, different flow in argon was studied by gas chromatography coupled with mass spectrometry （GC-MS）. The results showed that a large amounts of substances like alkene and alkYl compounds were produced at 700℃ or lower temperature, polycyclic aromatic hydrocarbons （PAHs） appeared in argon at 900℃. The higher the temperature is the more PAHs and alkyl-PAHs formed. The argon flow rate influenced the pyrolysis of polyethylene obviously. The experiment results confirmed the assumption that the olefin and alkyne are the precursor compounds of PAHs. Restraining the formation of the precursors such as olefin and alkyne is the key to reduce the release of PAHs.