Sugar in paper: Topochemistry and physics.

摘要

To reduce the amount of virgin pulp fiber in a paper is one of the key goals of the papermaking industries in their efforts to lower the cost of paper. The replacement of cellulose fibers with lower-cost simple sugars has therefore been proposed. The ability of simple sugars to function as a cellulose substitute has been examined by a study of the physical properties of paper in which part of cellulosic fibers has been replaced by a sugar.;Differential scanning calorimetry and edge-drying studies of sucrose-containing paper demonstrate that the sucrose molecule is hydrogen-bonded to the microporous cell walls of the pulp fiber and distributed uniformly throughout the paper. Relative to the sugar-free paper, the sucrose-containing counterparts exhibit greater tensile and tear index values as well as surface strength up to a sugar content of 10% w/w when the precursor pulp is refined (beaten) to particular levels. In contrast, no differences in moisture resistance or optical properties are observed between sucrose-containing and sugar-free paper.;Some other sugars also showed a positive contribution to the physical properties of the sugar-containing paper. From these results, it can be said that simple sugars can replace pulp fiber up to ca. 10% w/w depending on their molecular structure and the extent of refining of never-dried pulp fibers.;The incorporation of some disaccharides also remarkably strengthened the fiber and consequently contributed to the tearing resistance of the resultant paper. Since the mechanism to strengthen the sugar-impregnated fiber is based on the stereochemical interaction of the sugar molecule with the microporous cell wall of cellulosic fiber, the conformation and the distance of the OH groups located on the sugar molecule significantly affect the strength of the sugar-impregnated fiber.