Studies on Mannan in Wood Pulp

Part VIII. The Crystallinity of Glucomannan

Abstract

X-Ray analysis was carried out on a purified glucomannan specimen isolated from Akamatsu wood (Pinus densiflora SIEB. et ZUCC.). An X-ray diffraction diagram of a pure glucomannan showed a distinct crystalline pattern of undegraded glucomannan molecule having two diffraction points of 21° and 23° respectively but arabinoglucuronoxylan had no crystalline structure. An aqueous solution of purified glucomannan yielded characteristic skin-band when the solubility of the glucomannan was reduced. The skin-band indicated an optical anisotropic property under polarization microscope so that the skin-band was thought to consist of the ordered glucomannan molecules.