Thermal and thermo-oxidative degradation of high density polyethylene/fullerene composites

Fullerene (C-60)/high density polyethylene (HOPE) composites were studied in order to understand for their behaviors on thermal and thermo-oxidative degradation. Under different atmosphere, the influences of C-60 on the thermal stability of HDPE are different. Thermogravimetric analysis coupled to Fourier transform infrared spectroscopy (TG-FTIR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) demonstrate that in N-2 the addition of C-60 increases the onset decomposition temperature by about 10 degrees C with more heavy compounds (more than 34 carbon). Also the thermal stability of HDPE in air is remarkably improved with the addition of C-60. When the content of C-60 is 2.5 wt% the onset decomposition temperature increases by about 91 degrees C. The results of viscoelastic behavior and gel content reveal that C-60 can trap the alkyl radicals and alkyl peroxide radicals to inhibit hydrogen abstraction to suppress the chain scission and preserve the long chain structure. However, in the absence of C-60 or with low C-60 concentration, hydrogen abstraction occurs, resulting in the formation of a series of alkyl radicals and alkyl peroxide radicals, which accelerates the chain scission and plays a leading role in the thermal oxidative degradation. (C) 2013 Elsevier Ltd. All rights reserved.