Part I of the thesis describes extensive modifications made to a commercial analytical grade FT-IR instrument, in order to measure FT-Raman spectra in the NIR. The instrument was evaluated, and sample geometries and a range of accessories developed and assessed. A final prototype design for routine analysis is described. The FT-Raman method is simple and rapid to use, and ideally suited to the analytical laboratory. Part II describes the investigation of a wide range of polymer systems, from a basic identification / characterization viewpoint, to highlighting the advantages and drawbacks of the technique, and its feasibility, and the type of information available from polymers. In chapter 4A a general study of paint materials is summarized, and 3 industrially important problems are considered in more detail; the curing of alkyd resins, polymer latexes, and weathering. Kinetic information can be obtained from the FR-Raman spectra. In chapter 4B, a number of natural and synthetic elastomers are analyzed in their raw, blended, and crosslinked states. FT-Raman spectracan be used to rapidly determine microstructure in polybutadiene-based synthetic rubbers, and to follow the vulcanization process. Chapter 5 investigates the FT-vibrational spectra of a series of commercial polyethers, their copolymers, and composites. Compositional analysis of ES-EES copolymers, and the problem of obtaining crystallinity measurements in PEEK and its glass-fibre composites is discussed. FT-Raman spectroscopy can provide rapid determinations for both of these parameters. In Chapter 6 a range of novel thermotropic liquid crystal polyesters are analyzed. A series of spectroscopic variations with temperature and the thermal history of these materials can be related to the thermotropic behaviour, and the molecular structure of the crystal and liquid crystal phases is discussed.