title: Structure and thermal behavior of a cellulose I-ethylenediamine complex.
abstract: We prepared highly crystalline samples of a cellulose I-ethylenediamine (EDA) complex by immersing oriented films of algal (Cladophora) cellulose microcrystals in EDA at room temperature for a few days. The unit-cell parameters were determined to be a = 0.455, b = 1.133, and c = 1.037 nm (fiber repeat) and gamma = 94.02 degrees. The space group was P2(1). On the basis of unit cell, density, and thermogravimetry analyses, the asymmetric unit is composed of one anhydrous glucose residue and one EDA molecule. The chemical and thermal stabilities of the cellulose I-EDA complex were also investigated by the use of X-ray diffraction. When the cellulose I-EDA complex was immersed in methanol or water at room temperature, cellulose III I or I beta was obtained, respectively. However, immersion in a nonpolar solvent such as toluene did not affect the crystal structure of the complex. The cellulose I-EDA complex was stable up to a temperature of approximately 130 degrees C, whereas the boiling point of EDA is 117 degrees C. This thermal stability of the complex is probably caused by intermolecular hydrogen bonds between EDA molecules and cellulose. When heated above 150 degrees C, the cellulose I-EDA complex decomposed into cellulose I beta.
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan. awadam@mail.ecc.u-tokyo.ac.jp
authors.forename: Masahisa
authors.initials: M
authors.lastname: Wada
authors.forename: Gu Joong
authors.initials: GJ
authors.lastname: Kwon
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nishiyama
mesh_terms: D000641:Ammonia / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D003460:Crystallization; D005029:Ethylenediamines / Q000737:chemistry*; D056890:Eukaryota; D005947:Glucose / Q000737:chemistry; D006860:Hydrogen Bonding; D000432:Methanol / Q000737:chemistry; D008968:Molecular Conformation; D013696:Temperature; D013818:Thermogravimetry / Q000379:methods; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D005029:Ethylenediamines; D014867:Water; C031234:ethylenediamine; D000641:Ammonia; D002482:Cellulose; D005947:Glucose; D000432:Methanol