Abstract

In this study, analytical techniques were used for the characterization of acrylic and poly(vinyl acetate) (PVAc) products before and after accelerated aging and wet cleaning treatments.
For this purpose, analytical techniques such as Fourier Transformed Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR) and in-situ thermally assisted Pyrolysis-Silylation-Gas Chromatography-Mass Spectrometry (Py-Silylation-GC-MS) were used for chemical characterization. Scanning Electron Microscope with Energy Dispersion X-ray fluorescence analysis (SEM-EDX) and tensile tests were run for morphological and mechanical characterization. 
For studying the degradation processes caused by light exposure, a set of acrylic and PVAc products were subjected to two accelerated aging protocols. In order to represent normal aging conditions these were conducted at environmental Temperature (T) and Relative Humidity (RH) conditions. Consistent information on the aging of these products has been obtained by contrasting the resulting chemical and mechanical data from both aging programs. Specific degradation pathways such as chain-scissions or cross-linking were detected in this way. In general, acrylics were fairly more stable to artificial aging than PVAc and styrene-acrylics.
Finally, the effects of wet cleaning treatments were evaluated, with special focus on the action of water. Other cleaning treatments, comprising gels and emulsions were tested as well. The results indicate that water can cause changes in the morphology and mechanical properties of the samples as well as leaching of additives. These effects were significantly reduced when water was used in a gelled form. FTIR-ATR and Py-Silylation-GC-MS were used to study the additives extracted from the samples after cleaning treatments. Octyphenol and fatty alcohols non-ionic surfactants with poly(ethoxylated) chains have been detected, as well as anionic sulphonate type surfactants. Cellulose ether, poly(vinyl alcohol) and polyacrylic based thickeners were detected in the solid extracts from different test specimens.