Table 1-1 Chemical composition of some typical cellulose-containing materials a Others include extractives, inorganics (ash), protein, wax and pectin;

No abstract

No abstract

Various types of crystalline celluloses consisted of group I (Cell I, IIII, IVI) and group II (Cell II, IIIII, IVII) prepared from cotton linter were adjusted for their degree of polymerization (DP) as starting materials. These celluloses were, then, treated by semi-flow hot-compressed water (HCW) at 230-270˚C/10MPa/2-15min to study their decomposition behaviors. The treatments performed resulted in the residues of celluloses and watersoluble (WS) portions. Consequently, the crystallinity of the residues was found to remain the same, but the DP was reduced as temperature increased. Additionally, the X-ray diffractometry (XRD) and Fourier transforminfrared (FT-IR) analyses demonstrated that the crystallographic changes were occurred for residues of Cell IIII, IVI and IIIII. Despite of these changes, the overall results of the residues showed that group I has higher resistance to be decomposed than group II. As for the WS portions, the yields of the hydrolyzed and degraded products were more in group II as compared with group I, indicating that group II are lesser in resistance for their decomposition by HCW treatment. Both results on the residues and WS portions are in agreement with each other, concluding that the degree of difficulty for decomposition was higher in group I compared with group II. Therefore, the decomposition behaviors of the celluloses are due to the differences in crystalline forms.

No abstract