Analysis of thermal degradation kinetics and carbon structure changes of co-pyrolysis between macadamia nut shell and PET using thermogravimetric analysis and 13C solid state nuclear magnetic resonance
Analysis of thermal degradation kinetics and carbon structure changes of co-pyrolysis between macadamia nut shell and PET using thermogravimetric analysis and 13C solid state nuclear magnetic resonance
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DOI：
10.1016/j.enconman.2014.04.060
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发表时间：
2014-10-01
影响因子：
10.4
通讯作者：
Sahajwalla, Veena
中科院分区：
文献类型：
--
作者：
Ko, Kwang-Hyun;Rawal, Aditya;Sahajwalla, Veena
采用大型定制热重分析(TGA)和C-13固体核磁共振(核磁共振)谱研究了聚对苯二甲酸乙二酯(PET)与澳洲坚果壳共混物的热降解动力学。在N-2气氛中，升温速率分别为3℃/min、5℃/min、8℃/min至1273K，流量为1 L/min，分析了PET与澳洲坚果壳的共混比例为20-80wt.%。用Freeman-Carroll方法对差热分析(DTG)数据进行了分析，得到了动力学参数，并与C-13固体核磁共振的化学分析结果进行了关联。结果表明，在共热解过程中，PET与澳洲坚果壳之间存在两种协同效应，表现为共热解产物的碳产率提高。澳洲坚果壳一次产物与PET之间的二次反应是产生协同效应的原因，这种协同效应随共混物中澳洲坚果壳的质量分数和升温速率的不同而不同。活化能和反应级数的变化表明，共热解的热降解机理不同于单一组分的热降解机理。核磁共振结果表明，澳洲坚果壳催化了聚对苯二甲酸乙二醇酯的降解行为，导致多环芳烃(PAHs)的生成，从而提高了聚对苯二甲酸乙二酯的碳产率。(C)2014爱思唯尔有限公司。保留所有权利。
Thermal degradation kinetics of co-pyrolysis of polyethylene terephthalate (PET) blended with macadamia nut shell were investigated using a large-scale customised thermogravimetric analysis (TGA) and C-13 solid-state nuclear magnetic resonance (NMR) spectroscopy. Blending ratios ranging 20-80 wt.% of PET with macadamia nut shell were analysed at heating rates of 3, 5 and 8 degrees C/min up to 1273 K in the presence of N-2 atmosphere with a flow rate of 1 L/min. The differential thermogravimetric analysis (DTG) data was analysed by the Freeman-Carroll method to yield kinetic parameters which were correlated with chemical analysis by C-13 solid-state NMR. The results indicated that two synergistic effects occurred between PET and macadamia nut shell during co-pyrolysis, which were characterised by an enhanced carbon yield of the co-pyrolysis products. The secondary reaction occurring between primary products of macadamia nut shell and PET was identified as the cause of the synergistic effect and this effect varied with weight fraction of macadamia nut shell in the blend and the heating rate. The measured changes in activation energy and reaction order indicated that the thermal degradation mechanism of co-pyrolysis is different to that of the individual components. The NMR results indicated that macadamia nut shell catalysed the degradation behaviour of PET leading to growth of polycyclic aromatic hydrocarbons (PAHs) through cross-linking reaction and enhancing the carbon yield from the PET. (C) 2014 Elsevier Ltd. All rights reserved.