| Abstract:The paper produced from Broussonetia papyrifera fibers, due to their small cell lumens, exhibits excellent physical properties, rendering it an indispensable fiber material for art and restoration papers. However, the high aspect ratio of these fibers presents challenges in achieving uniform dispersion during use. The stability and preservation of existing papermaking additives designed to facilitate the dispersion of Broussonetia papyrifera fibers are poor, which can potentially impact the overall quality stability of the paper. To improve the quality of Broussonetia papyrifera paper and maintain the stability of the dispersant properties, this study analyzed the viscosity and molecular weight distribution of various dispersants (polyethylene oxide, anionic polyacrylamide, hydroxypropyl guar gum, Abelmoschus manihot gum, and compounded dispersant systems) and verified the dispersion effects of these dispersants on Broussonetia papyrifera fibers (drainage performance, paper sheet uniformity) and papermaking properties (physical properties, ink absorption performance). The compounded dispersant D1, composed of polyethylene oxide, hydroxypropyl guar gum, and Abelmoschus manihot gum, has been found to possess the most favorable properties. When incorporated at a concentration of 10%, it results in a drainage time of 32 seconds, and the viscosity remains stable at 387 mPa·s after 48 hours, with no significant alteration in molecular weight distribution. When 12% of D1 is added to untreated Broussonetia papyrifera fibers, the uniformity index of the paper reaches 137, the tensile index increases by 16.1%, the tear index by 18.5%, and the folding endurance improves from 51 times to 352 times. The ink roundness in the paper is 0.72, with a minor deviation in gray value, and the ink color within the paper is consistent. |