Ga. George et al., REAL-TIME ANALYSIS OF THE THERMAL-OXIDATION OF POLYOLEFINS BY FT-IR EMISSION, Polymer degradation and stability, 48(2), 1995, pp. 199-210
Quantitative FTIR-emission spectroscopy was applied to investigate the
real-time thermal oxidation of polyolefin samples and shown to be a u
seful method for studying polymer degradation. The high sensitivity of
the technique was demonstrated by studying the oxidation of individua
l pressed polypropylene (PP) and high-density polyethylene (HDPE) reac
tor powder particles and microtome cuttings of crosslinked polyethylen
e (XLPE). A detailed analysis of the growth in carbonyl bands during t
he degradation showed no changes in the product distribution with time
. Secondary oxidation products, such as gamma-lactones in the case of
polypropylene, were observed from the onset of the degradation, which
is consistent with a model of oxidation occurring in localized zones w
ith high reactivities. Differences in the oxidation sensitivity of the
se materials were identified and attributed to variations in the stabi
lity of the PP particles, catalyst residues in the HDPE and the degree
and method of crosslinking of the XLPE.