Investigations of the thermodegradation of ethylene-alpha-olefin copolymers by pyrolysis-gas chromatography (Py-GC)

The thermodegradation of several ethylene-alpha-olefin copolymers, where al pha-olefin was butene-1, hexene-1, octene-1 or 4-methyl-1-pentene, was inve stigated by the pyrolysis-gas chromatography (Py-GC) technique. The study o f the various pyrograms has allowed the discrimination of these polyethylen es (PEs) produced from different catalyst systems and processes. It was sho wn that the pyrolysis products could be classified into two families depend ing upon the type of the thermal degradation mechanism. In this way, it was demonstrated that, first, the nature and the amount of the comonomer, and, second, the long chain branching are the two structural features controlli ng the pyrolysis process. The quantitative ratio of these two families is a promising tool to classify the various polyethylene categories. In additio n, a statistical approach was applied to discriminate the different PE fami lies. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.