The Development of a Spectral Data Base for the Identification of Fibers by Infrared Microscopy

A detailed study of the application of infrared (IR) microscopy for single fiber analysis has been initiated. Spectra of single synthetic fibers were obtained rapidly and reproducibly with minimal sample preparation. Minor spectral variations, caused by deformation of the fibers during sample preparation, were observed between samples. These spectral variations were never sufficient to prevent the identification of the polymeric materials. An IR spectral library of 43 polymer fibers, which were distinguishable by their IR spectra, was constructed. The chemical subclass of unknown fibers, with the exception of acetates and nylons, could be accurately identified by a computer search using an absolute derivative difference searching algorithm.