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CHEMICAL PROPERTIES

المؤلف:  Max M. Houck، Jay A. Siegel

المصدر:  Fundamentals of Forensic Science

الجزء والصفحة:  p399-401

2026-08-16

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CHEMICAL PROPERTIES

While microscopy offers an accurate method of fiber examination, it is often necessary to confirm these observations. Analyzing the fibers chemically offers not only a confirmation of the microscopic work, but also may provide additional information about the specific polymer type or types that make up the fiber. For most of the generic poly mer classes, various subclasses exist that can assist in discriminating between optically similar ibers. FTIR and PGC are both methods of assessing the chemical structure of polymers. FTIR is the preferred method because it is not destructive of the fibers. Manufactured ibers also can be characterized by their reaction to certain chemicals; this method was popular prior to the introduction of instrumentation in crime laboratories. Solubility schemes tend to lack the specificity of instrumental methods and are destructive but can still be effective means to confirm a manufactured fiber’s generic class. Solubility tests should be performed on both the known and questioned fibers side by side either on a spot plate or on a microscope slide with a cover slip. A hot stage microscope may be required for some methods. Numerous solubility schemes exist, and one should be chosen with available chemicals, equipment, and safety in mind. One scheme is shown in Figure 1.

FIGURE 1 A solubility scheme for fibers.