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为阐明炭黑对聚合物在惰性气体中热行为的影响,研究了含聚乙烯(PE)、聚丙烯(PP)和聚异丁烯(PIB)的炭黑复合材料的热分解。通过热重法监测这样的复合材料和混合物的热稳定性,而复合材料的热解产物分布则通过高温分解气相色谱分析法/质谱分析法来测定。利用各种炭黑证实了这种影响取决于炭黑的挥发分含量。高挥发分的炭黑能引发PP、PIB的分解,而低挥发分的炭黑可提高聚合物的热稳定性。炭黑会影响聚合物的产物分布,其变化幅度随着炭黑挥发分的增加而增大。PE/炭黑复合材料中释放出较少的α,ω-链二烯和较多的n-链烷表明出现了氢化过程。PP的l-链烯低聚物的强度降低,而在PP/炭黑复合材料热分解期间形成了几种其它产物。这样的产物分布表明炭黑参与了氢转化反应。在PIB中观察到单体的演变增加,形成了受阻的低聚物。这样的现象可通过有炭黑存在的链端引发反应来解释。
To illustrate the effect of carbon black on the thermal behavior of polymers in inert gases, the thermal decomposition of carbon black composites containing polyethylene (PE), polypropylene (PP) and polyisobutylene (PIB) was studied. The thermal stability of such composites and blends was monitored by thermogravimetry, and the pyrolysis product distribution of the composites was determined by Pyrolysis Gas Chromatography / Mass Spectrometry. The use of various carbon blacks confirms that this effect depends on the volatile content of the carbon black. Highly volatile carbon black can cause the decomposition of PP, PIB, while the low volatile carbon black can improve the thermal stability of the polymer. Carbon black affects the polymer product distribution and increases with the volatility of carbon black. The liberation of less α, ω-alkadienes and more n-alkanes in the PE / carbon black composites suggests the hydrogenation process. The strength of the l-alkene oligomers of PP is reduced, while several other products are formed during the thermal decomposition of the PP / carbon black composite. Such product distribution indicates that carbon black is involved in the hydrogen conversion reaction. Monomer evolution was observed in PIB, forming blocked oligomers. This phenomenon can be explained by the presence of carbon black chain reaction.