The goal of this research was to determine whether mid-infrared (MIR) or near-IR could be used to determine the consistency of materials supplied within and between vendors, and whether physical characterizations could be correlated to the variations in the materials and to functional groups. IR spectroscopy is well known as an excellent tool for raw material qualification and structure-function determination. Both mid- and near-IR spectroscopy were applied to analyze the quality of resins used as raw materials.
The purposes of determining the quality of raw materials and QC tests are to either assure the raw materials are of sufficient quality, or to provide information to adjust the manufacturing processes to yield quality products. To do this, it needs to be determined whether the spectral differences are sufficient to characterize quality. If the differences are sufficient, calibrations can then be developed to screen raw materials or to provide information on whether and how a process needs to be adjusted so the product meets the critical quality parameters. Though quantitative analyses could possibly be done for the various components of these resin materials, qualitative analyses are sufficient, are equally sensitive, less time consuming and possibly more accurate than correlation to primary tests on components of low concentration.
The advantages of IR spectroscopy include rapid and accurate analyses due to fast and reproducible sample preparation. Longer tests lengthen production cycles, raise costs and lower output. This paper discusses the development of quick, easy, reproducible sample preparations that involved little waste for both MIR and NIR analyses of hard, modified resin materials. The goal was to develop qualitative tests that would be able to distinguish quality of resin with respect to functional groups within and between vendors, to identify chemical differences between the materials, and to investigate the feasibility of determining the effect of chemical content on physical properties.