Effect Of Metal Ions On Alkaline Degradation Of Cellobiose

Alkaline pulping was a process that plant fibers were dealt with in the mechanical and chemical processing, in pulping and papermaking industry. Cellulose fibers were needed protection from degradation in order to ensure products’ mechanical properties and physical properties, because cellulose fiber was an important part of pulp. At present, the cellulose alkaline degradation mechanism was not perfect, the research theory not very mature, plus cellulose macromolecular structure and its complex and changeable degradation reactions, so cellobiose was regarded as model of cellulose to be analyzed in this paper. That is to say, groping for alkaline degradation processing of cellulose was needed to be completed through the analysis of alkaline degradation of cellobiose.First of all, it was analyzed in this paper that effect of metal ions on the viscosity of cellulose in cotton fiber cooking with alkali. The mechanical properties of Cellulose fiber and paper were depended to a great extent on cellulose degree of polymerization. In different processing conditions (different kinds of metal ions, the same of other facts), weigh the weight of cotton fibers before and after cooked, calculate the absolute degradation of cotton fibers and measure the viscosity of cotton fibers before and after cooked through the copper ethylenediamine paste viscosity assay. The results showed that alkaline degradation of cotton fibers was promoted by K+and suppressed by Mg2+, Ca2+and Fe2+in a certain degree, at the technological conditions of reaction temperature160℃, NaOH dosage20%and liquor ratio40:1.Then, it was discussed in the paper that effect of metal ions on alkaline degradation of cellobiose. In this step, experimental conditions such as NaOH dosage, reaction temperature and reaction time were the first consider to be confirmed. It was discussed in the paper how metal ions effect on the alkaline degradation of cellobiose mainly from two aspects of reactant and product, namely cellobiose degradation and glucose producing. In this paper, two new concepts were defined in order to analyze, express and understand easily which were glucose producing rate and cellobiose degradation rate. The main principle examine equipment was High-performance Liquid Chromatography (HPLC), and the external standard method was used to measure the concentration of cellobiose and glucose. The results founded that alkaline degradation of cellobiose was promoted by K+, while suppressed by Mg2+and Ca2+. So there was a result that the effect of K+, Mg2+and Ca2+on alkaline degradation of cellobiose was in accordance with the effect of them on the viscosity of cellulose in cotton fiber cooking with alkali.