Thermal analysis for fiber identification and characterization

Fibers differ in their origin and chemical nature, their diameter, length, cross-section, surface contour, mechanical resistance, thermal stability, and color. All fibers are made up of macromolecules with their basic chemical unit being repeated hundreds or thousands of times. The structures of these units may be composed of homopolymers, block copolymers or branched copolymers with natural (plant, animal, or mineral) or synthetic origin. 

Thermal techniques including differential thermal analysis (DTA), thermogravimet-ric analysis (TGA), and thermomechanical analysis (TM A) are widely used in the characterization of polymers and fibers. The specific thermal behavior of a small amount of fiber sample may provide fingerprinting information that in itself is sufficient to identify a sample. These techniques may be complemented by other methods, including 

Optical or electron microscopy, infrared or fluorescence spectroscopy, or by traditional structural determination techniques to construct a complete profile of the sample. 

The objective of this chapter is to describe how thermal analysis can contribute to fiber identification and characterization. In order to achieve this objective it is necessary to understand how fibers are produced and how thermal history is impressed on these materials during production. The variety of commercial materials, manufacturing processes and additives used in the field of textile fibers renders a complete description impossible, however, an introduction to the principal aspects may be provided. 

Many of the treatments applied to alter the esthetic and functional performance also influence the thermal properties of fibers and it is therefore relevant to identify and comment on these processes. 

---