Multi-cell imaging chemiluminescence to map heterogeneous degradation of polypropylene plaques

摘要

The heterogeneity of the degradation of stabilized polypropylene (PP) plaques was studied using a recently designed multi-cell imaging chemiluminescence instrument. Mapping of the degradation of unaged PP plaques showed randomly distributed oxidation induction times (OIT), indicating random initiation presumably at polymerization catalyst residues. Contrary to this, hot-air oven aged PP plaques showed position related degradation. Zero OIT values were found at the edges, indicating complete oxidation, whereas the OIT increased towards the centre of the plaque. This non-random OIT distribution can be explained by a difference in evaporation rate of the stabilizer at different positions in the plaque.