Volume 35, Issue 2 (March 1990)
The Characterization of Plastic Automobile Bumper Bars Using Fourier Transform Infrared Spectroscopy (FTIR), Pyrolysis Gas Chromatography (PGC), and Energy Dispersive X-Ray Microanalysis Combined with a Scanning Electron Microscope (SEM-EDX)
A collection of 28 plastic automobile bumper bars has been examined using Fourier transform infrared spectroscopy (FTIR), pyrolysis gas chromatography (PGC), and energy dispersive X-ray microanalysis combined with a scanning electron microscope (SEM-EDX). FTIR identified 8 polymer classes in the collection. Polypropylene-based (PP) plastics and polyurethane (PUR) plastics were the most common with approximately three quarters of the samples being of these types. PGC provided additional discrimination between the samples in the collection, particularly for the PUR samples, defining a total of 13 categories. SEM-EDX was the most discriminatory technique used and resulted in 17 categories being identified. However, the combination of the 3 techniques of FTIR, PGC, and SEM-EDX was recommended as the preferred approach as it provided a high degree of discrimination with 25 categories identified. Vehicle identification via analytical profiles of bumper bar materials was not possible, and consequently, the establishment of a database using such information for investigative purposes could not be recommended.