SIMS investigation on the effect of the interstitial moisture in metallized polymer films

Dynamic SIMS depth profiling has been used to investigate the origin of the morphological and chemical degradation of metallized polymer films. The presence of the diverse oxidized species related to the main constituents of the metallization layer has been identified in samples exhibiting large decolourated regions. The in-depth analysis of these altered regions shows high contents of oxides and hydroxyl species (AlO⁺ and AlOH⁺). By comparison with pristine regions of the same sample, it has been demonstrated the pivotal role of interstitial moisture in the formation of the oxidized species in metallized polypropylene films. Care was taken to provide sufficient charge neutralization in the sample without an excess of electron flooding that could induce water emission by electron stimulated desorption.