FOLDED CHAIN STRUCTURE IN CELLULOSE MODIFICATIONS PREPARED FROM NATIVE CELLULOSE AND RAYON

Abstract

In the previous paper1) the possibility of molecular chain folding for cellulose molecule by accommodating in a molecular model and the fine structure in cellulose crystallite were discussed, and the folded chain model of Rayon was also presented on the ground of x-ray diffraction and acid hydrolysis studies.In the present paper, the folded chain structure of the various cellulose modifications derived from native cellulose and rayon is discussed. All cellulose modifications can be interpreted as the same fine structure of rayon, which consists of the folded chain molecule with the basic period of about 200A. However, the scheme of acid hydrolysis reaction of the most cellulose modifications from native cellulose differs from that of rayons: the molecular chains of cellulose I family are only hydrolyzed at each alternate folding part. Thus their levelling-off degrees of polymerization result in 80 corresponding to the chain length of about 400A.The difference between cellulose I and II family appears in the arrangements of a polarity of folded chains caused from a cellulose molecule itself. From the modeling consideration, there are two types in them: parallel and antiparallel. The former is resistant to acid, and the latter is accessible to acid. It is anticipated that the hydrogen bonding is only that of the latter type in cellulose II family and alternating the former and the latter types in cellulose I family.