XPS study of the changes during the service life of polyester powder coatings

Polyester powder coatings have been used for many years on architectural products, such as aluminium window trim. This study investigates the degradation mechanism of naturally weathered coatings that have been exposed to aggressive climatic conditions, including high ultraviolet radiation and coastal atmospheres containing salt. These conditions provide a harsh test regime over a period of 10 years, X-ray photoelectron spectroscopy (XPS) was useful for detecting the initial stages of coating degradation. The technique allows for the testing of new polymer coating materials under real conditions in much shorter time spans. The XPS study is supported by photoacoustic Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy. Copyright (C) 2002 John Wiley Sons, Ltd.