Abstract

The lignin content of pulp is determined from its diffuse reflectance infrared spectrum by an algorithm that calculates the degree of overlap between two spectra. The lignin:cellulose fraction correlates with kappa number, a titrimetric measure of lignin. Essentially no sample preparation is required, and the procedure is insensitive to variations in moisture content. The algorithm is able to detect changes induced by exposure of pulp to NO₂.

Recent applications of FT-IR spectroscopy to polymer systems

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