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Photo oxidation analysis method for automotive coating weathering performance evaluation
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
RESEARCH OBJECTIVE Accelerated artificial weathering performance has been always observed as critical and most important factor for durability prediction of colour and resin for a coating system. Photo oxidation of resin is the phenomenon behind coating’s ageing. Though accelerated weathering tests protocols are widely used in industry, they are very costly and still very time consuming. One automotive grade accelerated testing can go as long as 8 months duration. METHODOLOGY (maximum 150 words) Photo oxidation value (POV) is proportionate to the degradation of the resin material used in coating. During the accelerated weathering POV is measured for the coating at stipulated interval during initial phase and trend is plotted for deterioration verses weathering test duration. POV can be analysed with the help of FTIR analysis to observe bond absorption energy and bond separation energy in the resin system. This trend can be extrapolated to predict the weathering performance of coating. This method can save huge time in predicting the weathering performance and decision making. RESULTS (maximum 150 words) Photo oxidation degradation study was performed on polyester-based system and graphs were plotted considering area under FTIR graphs for wavelengths. Weathering was completed for 2500 hours and Further study is in progress for different resin system to plot photo oxidation values. LIMITATIONS OF THIS STUDY (maximum 100 words) These wavelengths for degradation will differ for each resin system and data base has to build in a form of library for each resin and each shade. For prediction of failure mode for a coating system, this data need to be build up over years along with weathering test results. WHAT DOES THE PAPER OFFER THAT IS NEW IN THE FIELD IN COMPARISON TO OTHER WORKS OF THE AUTHOR The effect of photooxidation on appearance parameters and predicting failure mode in terms of colour, wavescan profile and its analysis for different shades is covered in this paper which is one of its kind and unique.