The use of optical microscopy to follow the degradation of isotactic polypropylene (iPP) subjected to natural and accelerated ageing

摘要

Microscopy and mechanical properties are commonly used to follow the changes in morphology and mechanical resistance, respectively, of materials before and after any type of treatment. In this work, we used light microscopy (LM), scanning electron microscopy (SEM) and measurement of the mechanical properties to assess the natural ageing of samples of isotactic polypropylene (iPP) in Campinas and after exposure to Weather-Ometer type accelerated ageing equipment. The results obtained for the mechanical properties and by light microscopy (LM) allowed us to identify the ageing time based on the amount of radiation, for a 50% loss of elongation at break. The results were similar for samples subjected to the two types of ageing processes. Although a simple technique, LM was considered efficient when compared with SEM and the measurement of mechanical properties. (c) 2005 Elsevier Ltd. All rights reserved.