Nitrated Wood

Abstract

THE exact nature of the chemical components of wood and their relation to one another as they exist in the woody tissue is unknown. Wood is not a uniform mixture of cellulose, hemicelluloses, and lignin, since these substances are distributed in varying proportions in the different morphological parts of the tissue. Physical means of separating the cell wall components, such as extraction or solution and fractionation, are not possible. Chemical methods of isolating any of the constituents of wood are all drastic, and it is apparent that they result in isolated compounds which are altered from their original condition in the tissue. Chemical changes may be brought about in the •The photograph shows molding powders, films, lacquers, molded products, lacquer-finished articles, etc., prepared from nitrated sawdust.

The Fractionation of High-Polymeric Substances.

“…Coppick and Jahn (56) in 1943 made a study of nitrated wood, and described a procedure for fractionating nitrated spruce mechanical pulp by slow precipitation from acetone with alcohol and water. Eight fractions were obtained.…”

Photographic-Viscometric Apparatus and Technique

“…of the accuracy of the measurement of the flow times of dilute high-polymer solutions in conjunction with suitable calibration or correction of the viscometer will provide viscosity data which will make possible a more critical evaluation of the several methods of extrapolation (6,7,9) for obtaining intrinsic viscosities.…”

“…The realization of this end is, of course, based on a proper appreciation of the variables involved (1,4,6,10,13) and the development of apparatus embodying the inferred degrees of precision in the measurement or control of these variables. An outstanding treatment of this problem has already been provided by Jones and Talley (8).…”

Molecular Weight of Cellulose Measurement of Average Degree of Polymerization

“…For these relatively small amounts it would appear that a colorimetric method might be satisfactory for routine work. Feigl (2) found that lead dioxide oxidized nickel in alkaline solution to a valence higher than 2, and that addition of dimethylglyoxime to this solution gave a red coloration rather than a precipitate. This procedure was improved by Rollet U), who used bromine water instead of lead dioxide, and this method has found many applications (I, S, 5).…”

“…The publication of the Staudinger (11, 12,13) empirical viscosity-molecular -weight relationship gave great impetus to the investigation of methods for the determination of the weightaverage molecular weights of high polymeric compounds. Coppick (2) has recently reviewed and discussed the more significant papers that have been published relating the viscosity of solutions of high polymers with the degree of polymerization. The procedure most widely used is to relate viscosity data obtained at relatively high concentrations with the value of the viscosity function at infinite dilution through the use of mathematical equations (2, 4, 5, 6, 8, 14).…”