不同分子量高阳离子度瓜尔胶控制废纸浆微胶黏物的特性

制备了高阳离子度瓜尔胶（HCG），并对其进行酸降解，制得不同分子量级别的HCG。研究了它们作为废纸浆微胶黏物固着剂控制微胶黏物含量的效果以及它们对纸页物理强度性能的影响，结果表明：HCG的分子量越高，越容易吸附于纤维；分子量越低，越容易与浆料中的溶解与胶体物质作用。尽管不同分子量级别的HCG的电荷密度远小于常用的聚胺类固着剂，它们去除浆内胶体物质和COD成分的效果却等同甚至好于后者，说明HCG的作用机理还包括氢键作用等其它方式。在废纸浆中加入一定量分子量适当的高阳离子度瓜尔胶，在有效控制微胶黏物含量的同时，能抑制纸张抗张强度和撕裂强度的下降，对耐折度有一定的增强作用。

Characteristics of Highly Cationic Guar Gum with Different Molecular Weight in Controlling Microstickies in Recycled Pulp

Highly cationic guar gum(HCG) was prepared and acid hydrolyzed into different grades of HCG with lower molecule weights.The stickies control effects of these HCGs on newsprint recycled pulp were investigated,together with their influences on paper physical properties.The results showed that HCGs with higher moleculer weight were easier to be adsorbed onto cellulose fiber while HCGs with lower molecular weight were better to fix dissloved and colloidal substances.Despite that the HCGs had lower cationic density than commonly used fixing agents such as polyamine,their effect in decreasing colloidal substances and COD components were equal or even better than that of polyamine,indicating that the HCGs had additional microstickies controlling mechanisms such as hydrogen-bonding mechanism.Adding HCGs with proper molecular weight into recycled pulps can effectively remove microstickies components,yet tensile and tearing strengths can be maintained,and folding strength can be improved.