PHOTOACOUSTIC INFRARED-SPECTROSCOPY FOR EVALUATION OF AN ABS AS AN AUTOMOTIVE INTERIOR MATERIAL

Photoacoustic Fourier transform infrared spectroscopy (PAS-FTIR) has been demonstrated to be a chemical diagnostic tool to track the degradation of a commercial, fully formulated, molded acrylonitrile-butadiene-styrene material without special sample preparation. Samples obtained from plaques undergoing standard, natural and accelerated exposure as part of an on-going engineering study were examined. Additionally, a series of xenon are exposed samples with exposures according to the SAE J-1885 protocol were also examined to follow the relative rates of reaction for the changes observed above. Five days of xenon are exposure was approximately equal to 12 months exposure in Florida for this material. The decomposition process resulted in the formation of a brittle top layer similar to that seen in exterior exposure of this material. Photochemical oxidation was the cause of the decomposition and not heat. The decomposition was color independent for the three colors examined. A pigmented paint layer was found to protect the material from the photochemical process.