食品级聚碳酸酯的热释放成分和热分解机理研究

利用程序控温式热裂解-气相色谱/质谱联用技术研究了4种聚碳酸酯(PC)样品在加热情况下的释放物化学成分.分别考察了4个解吸温度和5个裂解温度下PC的降解产物.结果发现在200℃时PC粒料中就有小分子化学物质释放出来,随温度升高,释放和分解出的小分子化学成分的种类和数量都愈加增多,主要成分为酚端基化合物;由不同聚合工艺合成的聚碳酸酯中释放的化学成分有很大的差别.同时通过分析PC的裂解产物成分,阐述了其热分解机理.升温过程中PC分子链发生断裂和重排生成多种以酚类为主的小分子化合物.

STUDIES ON THERMAL DECOMPOSITION OF FOOD GRADE POLYCARBONATE

The thermal release products and thermal decomposition products of four food grade polycarbonate (PC) samples were studied by pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). The degradation products of PC samples were detected at difference desorption temperatures and different pyrolysis temperatures. The results showed that there was different between chemical components out-gassing from PC pellets polymerized with different methods; the initial out-gas was produced at 200℃ for all PC samples. Mainly phenol-end groups out-gas was produced. More chemical components produced at higher temperatures. The thermal decomposition mechanism was also explained by analyzing the pyrolysis products. During the pyrolysis process, PC molecular chains can be cleavaged and the fragments were rearranged. The pyrolysis products were mainly phenolic compounds. Whereas some phenolic compounds (for example bisphenue A) were harmful to human beings, The potential phenolic compounds in PC food package materials should be examined, and their special migration should be strictly limited.